The objective of this project is to not only thoroughly enhance my own knowledge on the subject of quantum physics, but also to inform others about it in a cohesive and easy to understand research paper that covers various topics.

I will be developing my knowledge in three sections.

First, for the "what", I will be answering the question of "What are the components of quantum physics?" I will be answering this question by doing several things. I will firstly be explaining many different aspects of quantum physics, such as entanglement and superposition, that are required in order to understand the rest of my project. I will also be covering different theories that we have in order to explain some uncertainties in this field, such as quantum field theory, in order to look at the issue from multiple perspectives and see which one I agree with the most.

Second, for the "why", I will tackle the question, "Why does quantum physics matter to society?" I will be exploring various technologies that use quantum mechanics, such as the electron microscope. In addition to that, I will provide a well thought-out hypothesis for what the future of quantum physics looks like.

For the final section, the "how", I will go in depth in answering "How does quantum computing work and what are quantum computers?" For this question, I hope to get insight from one or two professionals and learn about quantum computers and what advanced quantum technology like that might mean for classical computers and our everyday security.

Throughout all these sections, I am personally focused on looking a bit into the history between quantum discoveries and organizing the information in a way that is clear and easy to understand.

Here is the method that I used in order to have a clear and organized final research paper, which was the main objective of this project.

Research -

I will be splitting up my research into three parts in order to better organize and structure the information that I've collected. For each section, I will be first watching one or two general videos on the niche which I will explore before diving deep into each aspect that has been mentioned. For example, for section one, the "why", here were some of the steps I did (as recorded in my logbook). First step: watching "Quantum Physics for Seven Year Olds" by Dominic Walliman in order to aquire base-level information on specific parts of quantum physics. Second step: Focusing on one aspect mentioned; wave-functions. Third step: Exploring multiple sources and learning about wave-particle duality. Fourth step: Finding an experiment that proves this theory; the double slit experiment. Fifth step: doing an in-depth research on quantum numbers, which are used to describe the electron and making connections back to the original topics.

Data -

I will include several pictures (whether found online or hand-drawn) in order to visually communicate the information presented. I will also create various tables in order to make personal connections. For example, when learning about elementary particles and the fundamental quantum fields that make up the universe, I created a table where I organized all seventeen fields along with their spins, facts about them, and their electric charge. In doing so, I realised that twelve of them had a spin of 1/2, four had a spin of 1, and the outlier had a spin of 0. This led me to naturally grouping them together in my mind and doing the research to find out that the difference was because the twelve with a spin of 1/2 were fermions, the four with a spin of 1 were bosons, and the one left over was created in a lab and was its own subsection of boson.

Citing and fact-checking -

I have cited all my sources using MLA format in my logbook and they will be present at the in-person fair as well. When taking a sentence or an analogy from someone, I clearly stated their name and provided whatever credit was necessary. In order to make sure that my sources were trustworthy, I cross-checked all the information with other sources and identified the problem if anything didn't match up. For example, I saw in David Tong's talk at the Royal Institution ("Quantum Fields: The Real Building Blocks of the Universe") that he said there were three quarks in both a proton and a neutron, before showing an image of a proton with two up quarks and one down quark. I assumed that there were two up quarks and one down quark for both protons and neutrons alike, stating so in my initial research paper. However, on another occasion where I stumbled across the Wikipedia page for quarks, it said that there were in fact one up quark and two down quarks. It was only after further digging that I found that there were two up quarks in a proton and only one in a neutron. I also made sure to use information found through public forums sparingly unless the one providing the information had proper qualifications.

Logbook -

I recorded all information I learnt relevant to my project on my logbook, as well as how long I spent researching that day and the specific date. However, that being said, not everything I learnt was in the logbook, not everything in the logbook ended up in the final research paper, and not everything in the research paper will be presented at the fair. I really enjoyed reading Carlo Rovelli's fascinating novel "Helgoland: Making Sense of the Quantum Revolution", but most of the information present was either more history-oriented or already known at that point. For that reason, I didn't record what the chapters were about in my logbook, nor count the reading time as time spent on the project. Recordings of time were not exact but estimated appropriately, and I did not round up or down any more than five minutes. I only recorded the amount of time it took for my research on the website, but at the in-person fair I will add the time spent for making the trifold and presentation.

 

The What, Why and How of Quantum Physics

Erica McKinnon

Grade Nine

Branton School

 

The Basics of Quantum Physics

 

The word “quantum” is Latin for an amount or something that can be measured. Physics refers to science that deals with matter and energy, so quantum physics is the description of molecules, atoms and the smallest things that exist in the universe.

It was discovered in 1900, by the German theoretical physicist Max Planck. 

In 1918, Planck won the Nobel Prize in Physics for his theories and scientists all over the world are still studying his work to this day. Albert Einstein, following Planck’s logic, theorized that radiation was quantised apart from energy. There are still many things about quantum physics that remain unknown to us, but quantum physicists are working everyday to make new discoveries.

My research mainly follows the Copenhagen Interpretation, though it’s important to note that there are many different interpretations of quantum physics.

 

What are the components of quantum physics?

 

1A - Wavefunctions

 

Subatomic particles in the quantum realm can be pictured as waves of sorts called wavefunctions. Wavefunctions, as described by Dominic Walliman, is like dropping a pebble in a pond. The pebble in this scenario stands in for a particle and the ripples coming from it are like the waves. By some interference, picture the pebble coming up to the surface once more. This is probably the most basic explanation for wavefunctions. When the particle reappears, then we say the wave “collapses”. 

Due to something called wave-particle duality, physicists have concluded that wave and particle behavior are exhibited by all subatomic particles, such as protons, neutrons and electrons.

The wave function can only give us probability distributions, instead of the exact position of the particles, given that we still are yet to figure out how waves collapse. 

I’m certain that, in time, we will discover so much more about the quantum realm and uncover many things we can’t even fathom. However, let’s focus on more of the science that relates to the collapsing - where the particle will likely reappear, for instance.

Here’s how the quantum realm relates to mathematics, something which I found to be exceptionally interesting. If you take the amplitude of a wave-function squared, then it gives you a probability distribution. What probability distribution means is where the electron is likely and unlikely to end up once the wave collapses. It’s theoretically very likely that the electron goes toward the top of the wave, while it’s less likely for it to go towards the bottom of it.

To better understand wavefunctions, let’s take a look at the double-slit experiment. Imagine throwing paint at a wall with two slits in it. You would expect two stripes of paint to form on the back wall, wouldn’t you? 

Now, let’s repeat the experiment in the quantum realm. If you fire electrons at the same double-slitted wall, you’ll find something strange starts to happen. The electron waves will emerge from the slits in the wall, overlapping to form a grid of sorts. When the peaks of the waves meet, it reinforces the probability of the electron appearing there. When a peak is met with a trough or a trough meets a trough, there is low probability. This is called an interference pattern.

Because of the interference pattern, instead of simply having two regular stripes that line up with the slits in the wall, the electrons form multiple stripes instead. The same thing is true when you shine a light against the wall instead of firing electrons at it.

In figure (c), you can see a different angle of the experiment. From this point of view, there is zero probability of the electron ending up in any of the dark spaces and highest probability of it ending up in the brightest ones, such as in the middle. This is true even though there were initially no slits in that particular area.

You can see this in figure (a) as well, where the exact middle of the screen has high probability of the electron collapsing and the actual areas directly behind the slit have little to no probability. 

Note that in figure (b) the waves that hit the wall are in white, and where they cancel each other out is in blue.

According to the Copenhagen Interpretation (which I am basing most of my research off of), quantum particles exist in all states at the same time. This relies on the fact that because we have no evidence on how waves collapse into electrons and we assume that they are both waves and particles at once. These particles could be anywhere on the wave, meaning that they don’t exist in only one state, but at all of them. This state where the particles are in limbo is called superposition. 

One example is the famous Schrodinger’s Cat experiment. This was proposed by Erwin Schrodinger to prove a point. That’s because scientists at the time were speculating that waves only collapsed into particles when seen by a conscious observer, which Schrodinger found completely absurd.

He made up a hypothetical situation, where a cat was put in a box with some radioactive substance or something else with a fifty-fifty chance of killing the cat. Schrodinger made the claim that if you needed an observer to collapse waves, then technically the cat would be in a state of both alive and dead at the same time.

After Einstein drew the same conclusions, physicists have decided that Schrodinger was right and that the waves depending on an observer was a simply ridiculous idea. That being said, there are still many misconceptions about superposition in quantum physics.

Here is an image representation I drew to demonstrate this thought experiment. It’s not the best, but it gets the job done.

As stated by the Caltech Science Exchange, we can visualize superposition as a spinning coin or a mathematical equation. If you flipped a coin, it would land on either heads or tails. Superposition is kind of like the state of the coin when it’s spinning through the air - neither heads nor tails, and both at the same time.

Same goes for the mathematical equation that x squared is equal to four. There are more than one right answer - either two or negative two. While superposition isn’t that simple, these visualizations can help us to remember the basics - that superposition is the in-between state of particles.

 

2A - Quantum Numbers

 

Quantum numbers describe an electron, with four in total. These numbers are the principal quantum number, the angular momentum quantum number, the magnetic quantum number, and the spin quantum number.

The principal quantum number (n) demonstrates the energy of an electron as well as the size of its atomic orbital. The atomic orbital is the area around a nucleus where there is high probability of an electron being found. 

n is the description of the most probable distance of an electron in comparison to a nucleus. This means that the smaller value n holds, the closer to the nucleus and the smaller the atom. The atom will therefore have a bigger atomic orbital than if n were to hold a larger value. In other words, it determines the principal electron shell, or energy level.

n can be any integer greater than 1, with 1 being the lowest energy state. It is impossible for n to equal zero or less than zero because there are no atoms with no or negative energy levels.

An atom with n=1 would be in its ground state, but if the electron gains energy, it can jump into the second shell, in which case it would become in an excited state. The resulting shift to n=2 is called absorption, where the electron absorbs energy from photons. When the opposite happens, it’s called emission because it releases energy (photons of light).

The orbital angular momentum quantum number, also known as the Azimuthal quantum number (ℓ), is in charge of the orbital shape. 

There are four subshells when it comes to electron orbitals, which are the subshells s, p, d, and f. As you can see above, each orbital has a different shape and the subshell of the electron depends on the value of ℓ. The value of ℓ can be zero, unlike the principal quantum number n, but it can’t be in the negatives.

This is because the value of ℓ cannot be greater than n-1. For example, if ℓ was equal to 3 and therefore occupied the f subshell, n would at least have a value of 4. 

 

 

As you can see from the table above, there are many similarities between the results from each section.

Firstly, the number of angular nodes is determined by the value of ℓ. The picture near the start of this section shows angular nodes, which are usually at fixed angles.

For all the above subshells, there are no radial nodes. These only come up in higher subshells such as 2s or 2p.

Radial nodes are the space near the nucleus where there is zero probability of finding an electron. They look like rings around the nucleus.

In both the table and this diagram, you can see that 1s does not have any nodes, and it is only when it comes to 2s, 3s and higher levels when you see them form. In the picture depicting 1s, the electron has a probability of being found anywhere in that little purple circle. Kind of neat!

The equation for finding the number of radial nodes is n - 1 - ℓ, and the equation for finding the total number of nodes is n - 1. 

1s is the closest orbital to the nucleus and has the least amount of energy. 2s will be further away and with more energy, with 3s and 4s following.

You can also see that there are double the number of orbital electrons than the number of orbitals. That means that each orbital has two electrons for n=1. 

The magnetic quantum number (or mℓ) determines the number of electron orbitals in an atom and, consequently, the number of electrons. Its possible values depend on the value of the the Azimuthal quantum number ℓ.

It can be a negative integer, a positive one, or zero, but it always has a value between ℓ and -ℓ. The number of possible values of mℓ is equivalent to the number of orbitals.

 

3A - Quantum Tunneling

 

The phenomenon of quantum tunneling is basically when atoms, instead of bouncing off of each other, quantum-tunnel into each other instead. Here’s an analogy taken from Jane Tan-Holmes, the creator of the science Youtube channel Up and Atom.

If there are two hills and you are standing on one of them, you can push a ball down the first hill and it won’t ever make it over the second one because it doesn’t have enough potential energy.

However, if you replace the ball with an electron wave function, most of the wave will bounce off of the second hill like the ball would, but there is a chance that some of it will get inside the hill and make it out the other side. Now, that’s still just the wave function. On the other side of the hill, there’s a very small probability that the electron will get collapsed there, but it does happen. That’s why sometimes electrons can end up in the nucleus.

Something interesting about quantum tunneling is that it’s the very way the Sun creates energy. When two hydrogen atoms fuse and become helium instead of simply bouncing off of one another, it creates nuclear fusion, the very thing that gives us sunlight. 

It is also due to this that the Sun will eventually run out of hydrogen atoms to fuse. Because of quantum tunneling, it will turn into a white dwarf in six billion years. Luckily for us, though, humanity will probably already be extinct, meaning that we won’t have to suffer the inevitable repercussions. 

 

4A - Entanglement and Spin

 

In the words of Italian theoretical physicist Carlo Rovelli, entanglement is “the strangest of all strange quantum phenomena, the one that takes us furthest away from our old understanding of the world.”

Entanglement happens when two electron waves connect, or become “entangled”. They fuse into a single wavefunction, and however far away from each other they become, a measurement on one particle remains linked with a measurement on the other. 

One phenomenon of entanglement is what Einstein called “spooky action at a distance”. Here’s what that is. 

Each fundamental particle has spin, which basically means they own the properties of angular momentum and an orientation in space. Angular momentum is summarized by the equation L = mvr, where L is equal to angular momentum and m represents mass, v represents velocity, and r represents radius. 

Unlike linear momentum, which describes the inertia of an object that is in translational motion, angular momentum describes the inertia of something that is rotating.

When you measure the spin of a particle, there can be two outcomes. These can be described as “spin up” and “spin down”. (Spin up is a ½ spin and spin down is a -½ spin).

Spin down is classified as the outcome with the lowest energy, or the zero state. Quantum physicist Andrea Morello used the analogy of electrons being like compasses. It naturally points toward spin down, but you can push the needle to the opposite direction and you’ll have spin up, or the highest energy state.

Spin up is when the direction of measurement is aligned with the spin of a particle, and spin down is when it is opposite of the direction of measurement.

When you measure the spin of a particle vertically or at a perfect 90 degree angle, there is a fifty-fifty chance of it being spin up or spin down. The probability of getting spin up is equal to the square of the cosine of half the angle. This can be represented by the equation P(⬆️) = cos² (∠/2), where P is equivalent to the probability of spin up.

For example, if the spin of a particle is measured at 80 degrees from the vertical, then there is a 61 percent chance that the particle will be spin down and a 59 percent probability that it will be spin up.

However, when two particles are entangled, the second you measure one of them you instantly know that the spin of the second particle will be the opposite, as long as they are measured in the same direction. 

If these particles had a well-defined spin, then there would still be that fifty-fifty chance of them both having the same spin, but that would violate the law of conservation of momentum.

The law of conservation of angular momentum means that the spin speed of a system will remain constant unless there is interference from an external force.

Albert Einstein’s theory of special relativity states that the laws of physics stays the same for non-accelerating observers, and that, within a vacuum, the speed of light remains constant regardless of the speed of an observer.

When it comes to quantum mechanics, we don’t see entangled particles as having a well-defined spin, but rather see them as simply being opposite of each other. The second particle doesn’t have a spin until we measure the first one.

When this theory was first introduced, Einstein wasn’t happy with it because it suggested faster-than-light communication, something he ruled out with his theory of relativity.

He proposed that the particles had hidden information all along, like a secret plan to ensure that their spins are opposite. However, this theory was disproved by Bell’s theorem, though because the data always turned out random, quantum entanglement and “spooky action at a distance” didn’t violate Einstein’s theory of relativity.

 

4.5A - Spin Contd.

 

Spin also has a lot to do with mathematics. Different objects have different spins.

Quantum numbers have a spin of zero because it doesn’t matter how much you rotate the space around them, and the numbers don’t change in any way, shape or form. The Higgs Boson, which I will be mentioning in one of the following segments, also has a spin of zero, because it decays into protons which already have a spin of one themselves.

Vectors like the W boson and the Z boson (more on that later) point to a direction in space, and so rotation would change its appearance quite drastically. Vectors have a spin of one because they indicate a full turn alongside the space around them.

Spinors and leptons have a spin of ½ because space would need to do two full rotations in order for them to return to their original position.

 

5A - Antimatter

 

For every particle, there’s an antiparticle counterpart. They behave the same way as each other - same mass, spin, etc. - except they have opposite electric charges.

For example, the antiparticle of the electron, the positron, has all the same properties but a positive charge instead of a negative one. Particles like photons are their own antiparticles because they have zero charge.

When a particle and its antiparticle collide, they annihilate each other and create a massive amount of energy. This means that there should have been equal amounts of matter and antimatter after the Big Bang, though surprisingly that is not the case. Antimatter on Earth and in the universe is very well, and scientists are still trying to figure out why.

While I will say in the next segment that each proton has two up quarks and one down quark, that’s technically not completely true. In fact, there are hundreds, even thousands of quarks in a proton, just two more up quarks and one more down quark than the antimatter and matter particles that annihilate each other.

 

6A - Quantum Field Theory

 

While it might seem like protons, neutrons, electrons and quarks are the fundamental building blocks of everything in the universe, quantum field theory suggests something else.

According to quantum field theory, everything that we see and touch is made up of fluid-like substances called fields which ripple and interact with each other to make up the universe.

A quantum field can be best explained in the words of renowned Cambridge professor David Tong. It is “something that takes a particular value at every point in space. [...] That value can change in time.”

There are electric fields (that form around particles charged with electricity), and magnetic fields (that form around magnets with magnetic force). Ripples in these fields form what we see as light. The quantum of the electric field, photons, are what you get when you look closer at light waves.

There’s another field called the electron field that fills the universe, and the ripples coming from this field are the electrons, which is basically the same concept as the protons from earlier.

In every proton and neutron, there are three quarks - two up quarks and one down quark for a proton, and one up quark and two down quarks for a neutron. There are two quark fields as well, one field for up quarks and another for down quarks. As you might guess, the up quarks and down quarks are resulting from the ripples from their respective fields. According to quantum field theory, this is true for every particle in the universe.

The Heisenberg Uncertainty Principle states that it is impossible to know the exact speed and location of a particle. The more you know about its speed, the lower the accuracy of its location, and vice versa.

Because of this principle, there are always fluctuations in quantum fields. These are called quantum vacuum fluctuations. We can measure these fluctuations and see that they produce energy.

Aside from the electron field and the two quark fields, there’s a fourth field, which is the neutrino field.

Neutrinos are everywhere in the universe, produced whenever atomic nuclei collide or break apart. They don’t seem to interact with anything, with tens of trillions of them streaming through our bodies by the second without us ever feeling anything.

In total, there are twelve quantum fields that give matter, called fermions. Fermions have half-integer spins such as ½. The electron, the electron neutrino, the up quark, and the down quark are the ones we are most familiar with. However, there’s also the muon and the tau, the muon neutrino and the tau neutrino, the strange quark and the charm quark, and the top quark and bottom quark.

If you make them into a table, you’ll get something a little like this.

 

THE TWELVE FUNDAMENTAL FERMIONS

 

Aside from these, there are five other fields which are the forces, or the bosons. These are the gluon field, the higgs field, the photon field, and the W boson and Z boson fields. They have integer spins like zero or one. If we add them to our table, it’ll look a little something like this.

 

Red - Fermions    Yellow - Bosons    Purple - Boson?  

*2.4 x 10⁴ the size of an electron

 

 

*In a proton, there are two up quarks and one down quarks. Since ⅔ + ⅔ - ⅓ is equal to 1, protons have a total electric charge of one. There are one up quark and two down quarks in a neutron, which is why they have an electric charge of zero.

**The Higgs boson is unique because it has zero spin, electric charge, and strong force interaction. It came into existence in a lab for only a very short time before decaying into different particles.

***The Higgs boson is also the only scalar boson we have so far in the Standard model. 

 

Why does quantum physics matter to society?

 

1B - Electron Microscopes

 

Electron microscopes were invented because optical microscopes, which used light, had a very limited capacity to zoom in on objects. This is because the wavelength of light is fairly wide compared to the wavelength of an electron, which means that there will be less diffraction and, consequently, a higher resolution image.

Each electron microscope works by shooting a beam of electrons at a sample which goes through electromagnetic lenses and hits the sample, where secondary electrons fly off upon contact with it.

Electron microscopes come in two types, which are the SEM (scanning electron microscope) and the TEM (or transmission electron microscope).

The SEM can magnify the sample from five to five hundred thousand times, and shows detailed and clear images of the features on the surface. The beam of electrons scans the sample and after hitting it, scattered electrons (also known as secondary electrons) fly off of it and are detected and converted into light signals.

To prepare the sample for a SEM, it needs to be covered in a very light layer of conductive material such as metal in order to improve the quality of the image.

The TEM can magnify the sample from fifty to fifty million times, which is way more than the capacity of the SEM. However, the images produced do not show the texture of the surface and instead look flat, which is less useful in some cases. 

The samples are required to be extra thin so that the electrons can pass straight through them.

 All that is only possible because of quantum physics and our understanding of wave-particle duality, which led us to experimenting with the wave properties of electrons and inventing the electron microscope. This microscope will no doubt help us gain even more information on the quantum realm and help us observe objects on the molecular level.

 

2B - Superconductors

 

Normally, objects are either insulators, semiconductors or conductors. This is because when electrons travel through the atom lattice of a material, they bump into each other and cause a chain reaction, losing energy in the process.

However, when the material reaches extremely low temperatures such as 77 Kelvin, the atoms move around a lot less and the electrons can easily slide through the lattice without losing any energy.

That is made possible by what’s called Cooper pairs. Normally, electrons have a half-integer spin, which makes them fermions, meaning that they can only have two in the same state at once (one with a spin of ½ and another with a spin of -½). This is also the reason why there are two electrons in each shell.

Despite that, in superconductors electrons can actually form into Cooper pairs, where together they have integer spins and become bosons, which means they are in their lowest energy state. Because they are already in the lowest energy state, it is impossible for them to lose any energy and therefore electrons can travel through the lattice without any trouble, essentially creating infinite energy until the material is heated up again.

Superconductivity is also able to manipulate electric fields. Normally, when you place a magnet on top of a material, the magnetic field passes right through it and nothing happens. However, if you repeat the same process with a superconductor, the magnetic field is unable to penetrate the superconductor and instead pushes against it, resulting in what seems to be magical levitation. 

We can take advantage of this extraordinary phenomenon with real world applications, such as the Maglev train, which levitates over guideways and therefore eliminates the possibility of a bumpy ride and the friction that normally accompanies train rides. 

Superconductors could not have been possible without the knowledge on how electrons and atoms work on a quantum level. Due to our extensive research on quantum physics, we have been able to do things we didn’t think we could before, such as real-world levitation.

 

3B - MRI Scanners

 

MRIs are used in hospitals to create detailed and precise images of internal organs, muscles, and bone structure. They are extremely useful when it comes to detecting cancer and other diseases.

The key to understanding how they work is understanding two quantum properties - one, spin, which we’ve discussed already - and two, nuclear precession.

Nuclear precession is a wobbling motion created by the gravitational field of the Earth, where protons move similarly to a spinning top. There’s a lot more to it than just that, but it’s all that’s needed to understand the basics of MRI scanners.

MRIs are like one big magnet that generates its own magnetic field. Because our bodies are made up of 60 percent water, there are billions of hydrogen protons inside of us.

The magnetic field emitted by the MRI aligns all the protons in one direction. Afterward, a radiofrequency pulse (otherwise known as rf pulse) forces the protons to precess in sync with each other.

After the rf pulse, the radio waves from the MRI turn off and the protons return to their original positions, while releasing energy in a process known as relaxation.

The coils in the MRI machine process the information from the protons in order to create detailed images.

Because of our understanding of spin and precession, we can accurately detect tumors, cancer and much more. We can apply our knowledge on quantum properties in the real world and, more than that, save lives, which I find very awesome. 

 

4B - Prediction

 

Within 15 years, I believe that the number of quantum computers will multiply substantially and nearly all countries will be involved in further development of quantum computers, quantum technologies, and quantum research.

We will no longer be using the same methods of encryption, given that quantum computers could decrypt any password or security system within seconds.

I highly doubt that quantum computers will replace classical computers in the future because they still have different uses and, though there are many different ways in which quantum computers are much more powerful, they will still be fairly expensive even thirty years from now.

Within a decade, I think that we are going to start merging quantum technology with artificial intelligence, which could both be fairly dangerous and frightening and life saving at the same time.

For example, the fusion of quantum and artificial intelligence could help us create faster and personalized vaccines that respond immediately to life-changing threats and conditions. However, this powerful technology also brings into question whether or not we will be able to fully control this technology or control it at all, with the presence of machine learning and ability to quickly adapt to new challenges.

 

How does quantum computing work and what are quantum computers?

 

 

1C - What Quantum Computers Are

 

Basically, while classical computers have classical bits that can either be in a state of 0 or 1, quantum computers have quantum bits (or qubits for short) which can be any combination of states between 0 and 1 at the same time because of quantum superposition.

This means that quantum computers can, as stated in my prediction, decrypt security systems way faster than the classical computers and supercomputers of today.

Even supercomputers, which are more powerful and faster than regular computers that can be used for advanced simulations, run off of the binary code that classical computers do. 

Transistors, which are tiny switches that can block or allow access in circuits, used to be fairly big. However, as time went on we’ve developed smaller transistors, and smaller computers. Now, transistors are nearing the size of atoms.

This is a problem because of quantum tunneling. Because electrons can quantum-tunnel through physical barriers, this means that transistors can’t get any smaller. 

Transistors are necessary because they make up logic gates, which are the building blocks of digital circuits.

You’d think that that means there is no way to make computers any more powerful, but that’s where quantum computers come into play.

 

2C - How Quantum Computers Work

 

When you see images of quantum computers on the Internet, the bulk of it is made up of cooling pipes and not actually the qubits themselves.

That’s because the information contained in these qubits can be very easily destroyed. A cryogenic environment makes sure to limit noise, disturbance, and vibrations that might harm the delicate qubits.

Qubits are actually placed in quantum computing chips in three different ways.

The first way is by using a superconducting circuit, which utilizes the unlimited electron flow of superconductors to harness qubits. Superconducting circuits use technology fairly similar to that found in classical computers, which is an advantage.

The second way of making quantum computing chips is used for trapped ion quantum computers. In this case, the qubits are, as the name suggests, ions that have been stripped of one electron and can be manipulated by magnetic and electric fields. Much like the Maglev trains that I mentioned before, there are alternative voltages for the electrodes next to the ion and the rest are connected to the ground. This means that the ion has nowhere else to go because opposites attract and it is surrounded by alternative voltages. These qubits are much more stable and can be easily entangled.

The third way is by using photons of light as qubits. This way can be done at room temperature, which is a huge plus, but it’s difficult to have multiple qubits at once and for a longer period of time.

 

3C - The Impact of Quantum Computers

 

By using pipettes to transfer human lung cells and using them to simulate actual organs, quantum computers can help us to not only create more effective drugs, but to even personalize treatments for specific patients.

For example, in between treatments, researchers could take tissue cells from someone with cancer. They could then use the quantum computer to try all possible treatments at once and see which cocktail is the most effective and least dangerous one for the patient.

This is also much more ethical than testing treatments on animals, because every year more than 115 million animals are tested in laboratories. In addition to that, results from animal testing are less than 50% accurate when compared with human results. This also makes quantum computers a much more effective choice.

However, on the flip side, as I mentioned before, quantum computers have the potential to break all encryption and put everyone’s safety at risk of being hacked.

This is because most of everything that we use for our passwords, bank accounts, and other security systems use Shor’s algorithm, where they use absurdly long numbers with two, three hundred digits. You can only break the system by finding the two factors that make that long number, which is next to impossible, even with a supercomputer.

However, due to quantum superposition, the quantum computer can test all possible combinations at the same time and find the right one in almost an instant.

Despite this, there are other ways of encryption that utilize quantum mechanics to their advantage, which means that this likely won’t be that much of a problem in the future.

 

 

 

Max Planck, German theoretical physicist and father of quantum physics

The double-slit experiment which proves particle-wave duality

A visual representation of Shrodinger's cat

A diagram which demonstrates electron shells and the principal quantum number n

An image of the different kinds of atomic orbitals, which have shapes controlled by the Azimuthal quantum number

After finishing my project, I have found the answers to my initial three questions and completed the goal of my project.

What are the components of quantum physics?

Quantum physics is made up of several aspects. These aspects include particle-wave duality, quantum numbers, quantum tunneling, entanglement, spin, and antimatter. There are many different interpretations of quantum physics, which include the popular Copenhagen interpretation, quantum field theory, and Carlo Rovelli's relational interpretation. 

Why does quantum physics matter to society?

There are so many things we use today that exist only because of quantum physics, such as MRI scanners and electron microscopes. This is only the tip of the iceberg when it comes to quantum technology, and quantum computers are already solving problems like never before. The quantum revolution is starting to make us question things such as our security systems, because they can easily be broken with the use of quantum computers.

How does quantum computing work and what are quantum computers?

Quantum computers are not necessarily better computers, because there are still problems that classical computers are more fit to compute. However, quantum superposition allows for higher efficiency in several areas such as security and in the pharmaceutical industry. They work on qubits instead of classical bits, which mean that they don't just need to be 1 or 0, but can be anything in between.

CITATIONS

“Quantum Physics for 7 Year Olds | Dominic Walliman | Tedxeastvan.” YouTube, 24 May 2016, www.youtube.com/watch?v=ARWBdfWpDyc. 

“If You Don’t Understand Quantum Physics, Try This!” YouTube, 25 Feb. 2019, www.youtube.com/watch?v=Usu9xZfabPM. 

“The Interpretations of Quantum Mechanics.” YouTube, 3 Apr. 2019, www.youtube.com/watch?v=mqofuYCz9gs. 

Labmate, International. “What Is Quantum Physics and Who Invented It?” Labmate Online, www.labmate-online.com/news/news-and-views/5/breaking-news/what-is-quantum-physics-and-who-invented-it/39423#:~:text=Its%20origins%20can%20be%20traced,to%20the%20German%20Physical%20Society. Accessed 15 July 2023. 

“7.2: Wave Functions.” Physics LibreTexts, 12 Sept. 2022, phys.libretexts.org/Bookshelves/University_Physics/Book%3A_University_Physics_(OpenStax)/University_Physics_III_-_Optics_and_Modern_Physics_(OpenStax)/07%3A_Quantum_Mechanics/7.02%3A_Wavefunctions. 

Hatfield, Miles. “Why the Sun Won’t Become a Black Hole.” NASA, 25 Sept. 2019, www.nasa.gov/image-feature/goddard/2019/why-the-sun-wont-become-a-black-hole. 

“Physics in a Minute: The Double Slit Experiment.” Plus Maths, 19 Nov. 1970, plus.maths.org/content/physics-minute-double-slit-experiment-0. 

Owen.pham. “Copenhagen Interpretation of Quantum Mechanics.” Wondrium Daily, 28 Dec. 2020, www.wondriumdaily.com/copenhagen-interpretation-of-quantum-mechanics/#:~:text=Q%3A%20What%20is%20the%20Copenhagen,the%20reality%20of%20the%20state. 

“What Did Schrodinger’s Cat Experiment Prove?” Science Questions with Surprising Answers, www.wtamu.edu/~cbaird/sq/2013/07/30/what-did-schrodingers-cat-experiment-prove/. Accessed 20 July 2023. 

Crouch, Jennifer. “Schrodinger and the Wave Equation.” Instant Science, Printers Row Publishing Group, New York, 2020. 

“What Is Superposition and Why Is It Important?” Caltech Science Exchange, scienceexchange.caltech.edu/topics/quantum-science-explained/quantum-superposition. Accessed 23 July 2023. 

“Quantum Entanglement & Spooky Action at a Distance.” YouTube, 12 Jan. 2015, www.youtube.com/watch?v=ZuvK-od647c. 

Jonathan. (2019, May 22). Theory of relativity. AllAboutScience.org. https://www.allaboutscience.org/theory-of-relativity.htm 

Tillman, N. T., Bartels, M., & Dutfield, S. (2022, January 5). What is the theory of general relativity?. Space.com. https://www.space.com/17661-theory-general-relativity.html 

YouTube. (2019, May 29). Do you really understand Einstein’s theory of relativity? - BBC News. YouTube. https://www.youtube.com/watch?v=B6kreUskcpo 

Khan Academy. (n.d.). Conservation of angular momentum (video). Khan Academy. https://www.khanacademy.org/science/mechanics-essentials/xafb2c8d81b6e70e3:why-do-helicopters-have-a-second-rotor-on-the-tail/xafb2c8d81b6e70e3:why-do-helicopeters-have-a-second-rotor-on-the-tail/v/conservation-of-angular-momentum 

YouTube. (2015, January 22). What is angular momentum?. YouTube. https://www.youtube.com/watch?v=iWSu6U0Ujs8 

Sheldon, R. (2022, June 1). What is conservation of angular momentum?. WhatIs.com. https://www.techtarget.com/whatis/definition/conservation-of-angular-momentum#:~:text=Conservation%20of%20angular%20momentum%20is,as%20net%20torque%20is%20zero. 

“What Is Angular Momentum?” YouTube, YouTube, 29 Nov. 2018, www.youtube.com/watch?v=4GgJ6EgAmFg. 

“Bell’s Theorem.” Wikipedia, Wikimedia Foundation, 18 Aug. 2023, en.wikipedia.org/wiki/Bell%27s_theorem. 

“How Does a Quantum Computer Work?” YouTube, YouTube, 17 June 2013, www.youtube.com/watch?v=g_IaVepNDT4. 

“Electron Spin.” Chemistry LibreTexts, Libretexts, 22 Oct. 2023, chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Quantum_Mechanics/09._The_Hydrogen_Atom/Atomic_Theory/Electrons_in_Atoms/Electron_Spin#:~:text=So%2C%20the%20first%20electron%20one,each%20of%20the%20three%20orbitals. 

ROVELLI, CARLO. “The Web of Relations That Weaves Reality.” Helgoland: Making Sense of the Quantum Revolution, RIVERHEAD BOOKS, S.l., 2022, pp. 89–113. 

“Quantum Field Theory Visualized.” YouTube, YouTube, 31 Oct. 2020, www.youtube.com/watch?v=MmG2ah5Df4g. 

“Quantum Fields: The Real Building Blocks of the Universe - with David Tong.” YouTube, YouTube, 15 Feb. 2017, www.youtube.com/watch?v=zNVQfWC_evg. 

“Magnetism.” Education, education.nationalgeographic.org/resource/magnetism/. Accessed 1 Jan. 2024. 

“Photon.” Wikipedia, Wikimedia Foundation, 16 Dec. 2023, en.wikipedia.org/wiki/Photon#:~:text=A%20photon%20(from%20Ancient%20Greek,carrier%20for%20the%20electromagnetic%20force. 

ROVELLI, CARLO. “The Absurd Idea of the Young Heisenberg: Observables.” Helgoland: Making Sense of the Quantum Revolution, RIVERHEAD BOOKS, S.l., 2022, pp. 3–19. 

“What Is the Uncertainty Principle and Why Is It Important?” Caltech Science Exchange, scienceexchange.caltech.edu/topics/quantum-science-explained/uncertainty-principle#:~:text=Formulated%20by%20the%20German%20physicist,about%20its%20speed%20and%20vice. Accessed 2 Jan. 2024. 

“What Is the Heisenberg Uncertainty Principle? - Chad Orzel.” YouTube, YouTube, 16 Sept. 2014, www.youtube.com/watch?v=TQKELOE9eY4. 

“Vacuum Fluctuations: Measuring the Unreal.” NIST, 20 July 2018, www.nist.gov/news-events/news/2015/06/vacuum-fluctuations-measuring-unreal. 

Piermatteo, et al. “Quantum Fluctuations and Their Energy.” Of Particular Significance, 4 Sept. 2022, profmattstrassler.com/articles-and-posts/particle-physics-basics/quantum-fluctuations-and-their-energy/. 

“Doe Explains...Neutrinos.” Energy.Gov, www.energy.gov/science/doe-explainsneutrinos#:~:text=Neutrinos%20are%20the%20most%20abundant,the%20potassium%20in%20the%20fruit. Accessed 2 Jan. 2024. 

Healy, John. “Physics Says What?” Physics Says What, 18 Oct. 2023, www.physicssayswhat.com/2019/06/05/qft-how-many-fields-are-there/. 

“The Higgs Boson: A Landmark Discovery.” ATLAS Experiment at CERN, atlas.cern/Discover/Physics/Higgs#:~:text=In%20the%20Standard%20Model%2C%20the,the%20particles%20it%20decayed%20to. Accessed 2 Jan. 2024. 

“What Is Quantum Field Theory?” David Tong -- What Is Quantum Field Theory?, www.damtp.cam.ac.uk/user/tong/whatisqft.html. Accessed 3 Jan. 2024. 

Strogatz, Steven, and substantive Quanta Magazine moderates comments to facilitate an informed. “What Is Quantum Field Theory and Why Is It Incomplete?” Quanta Magazine, 24 Aug. 2022, www.quantamagazine.org/what-is-quantum-field-theory-and-why-is-it-incomplete-20220810/. 

“Gluon.” Gluon - an Overview | ScienceDirect Topics, www.sciencedirect.com/topics/earth-and-planetary-sciences/gluon. Accessed 3 Jan. 2024. 

“Gluon.” Encyclopædia Britannica, Encyclopædia Britannica, inc., www.britannica.com/science/gluon. Accessed 3 Jan. 2024. 

“Doe Explains...Muons.” Energy.Gov, www.energy.gov/science/doe-explainsmuons. Accessed 3 Jan. 2024. 

“Subatomic Particles, Part 4: Gauge Bosons, the Glue That Holds the Universe Together.” The Institute for Creation Research, www.icr.org/article/subatomic-particles-part-4-gauge-bosons. Accessed 3 Jan. 2024. 

“The Higgs Boson: Revealing Nature’s Secrets.” CERN, home.cern/news/series/lhc-physics-ten/higgs-boson-revealing-natures-secrets#:~:text=At%20the%20time%20of%20the,two%20spins%20of%20the%20photon. Accessed 4 Jan. 2024. 

Boudreaux, Kevin A. Quantum Numbers, Atomic Orbitals, and Electron Configurations, www.angelo.edu/faculty/kboudrea/general/quantum_numbers/Quantum_Numbers.htm#:~:text=Each%20electron%20in%20an%20atom,electrons%20can%20occupy%20that%20orbital. Accessed 4 Jan. 2024. 

“Q&A - Quantum Fields: The Real Building Blocks of the Universe - with David Tong.” YouTube, YouTube, 15 Feb. 2017, www.youtube.com/watch?v=QUMeKDlgKmk. 

“Quantum Numbers for Atoms.” Chemistry LibreTexts, Libretexts, 30 Jan. 2023, chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Quantum_Mechanics/10%3A_Multi-electron_Atoms/Quantum_Numbers_for_Atoms#:~:text=The%20principal%20quantum%20number%2C%20n,the%20shape%20of%20the%20orbital. 

Dhali, Dipa. “Atomic Orbital: Definition, Types, Shapes, and Diagram.” Science Facts, 2 Feb. 2023, www.sciencefacts.net/atomic-orbital.html. 

Learning, Lumen. “Physics.” Young’s Double Slit Experiment | Physics, courses.lumenlearning.com/suny-physics/chapter/27-3-youngs-double-slit-experiment/. Accessed 4 Jan. 2024. 

“Radial and Angular Nodes Formula.” Unacademy, 15 Nov. 2022, unacademy.com/content/jee/study-material/chemistry/radial-and-angular-nodes-formula/#:~:text=Angular%20nodes%20are%20usually%20equal,of%20nodes%20%3D%20n%20%E2%80%93%201. 

Admin. “Radial and Angular Nodes Formula - Definitions, Formula, Calculations, Examples, Diagram , with Videos and Faqs of Radial and Angular Nodes Formula.” BYJUS, BYJU’S, 2 Aug. 2022, byjus.com/chemistry/radial-and-angular-nodes-formula/#:~:text=for%20Angular%20nodes-,The%20planes%20or%20planar%20areas%20around%20the%20nucleus%20where%20the,of%20the%20azimuthal%20quantum%20number. 

Darling, David. “Quantum Number.” The Worlds of David Darling, www.daviddarling.info/encyclopedia/Q/quantum_number.html. Accessed 15 Jan. 2024. 

“Spin Quantum Number | Overview & Examples - Study.Com.” Study.Com, 2023, study.com/academy/lesson/spin-quantum-number-definition-example-quiz.html. 

“What Is Quantum Tunneling, Exactly?” YouTube, YouTube, 9 Oct. 2018, www.youtube.com/watch?v=WPZLRtyvEqo. 

CERN accelerating science. CERN. (n.d.). https://home.cern/science/physics/antimatter 

Mann, A. (2021, December 13). What is antimatter?. LiveScience. https://www.livescience.com/32387-what-is-antimatter.html 

Veterans Affairs. Go to VA.gov. (2010, February 22). https://www.va.gov/DIAGNOSTICEM/What_Is_Electron_Microscopy_and_How_Does_It_Work.asp 

Scanning electron microscopes. Thermo Fisher Scientific - US. (n.d.). https://www.thermofisher.com/ca/en/home/electron-microscopy/products/scanning-electron-microscopes.html 

“Electron Microscope | TEM | SEM | Cryo Em.” YouTube, YouTube, 2 May 2019, www.youtube.com/watch?v=t4hhdgJADE8. 

“Scanning Electron Microscopy (SEM).” Techniques, 19 Oct. 2023, serc.carleton.edu/research_education/geochemsheets/techniques/SEM.html#:~:text=The%20scanning%20electron%20microscope%20(SEM,the%20surface%20of%20solid%20specimens. 

“The Map of Superconductivity.” YouTube, YouTube, 3 July 2021, www.youtube.com/watch?v=bD2M7P6dTVA. 

“How Do Superconductors Work at the Quantum Level?” YouTube, YouTube, 3 Apr. 2021, www.youtube.com/watch?v=vruYFOlM1-Q. 

“What Is a Superconductor?” Built In, builtin.com/hardware/superconductor. Accessed 29 Feb. 2024. 

Bonsor, Kevin, and Nathan Chandler. “How Maglev Trains Work.” HowStuffWorks Science, HowStuffWorks, 15 Aug. 2023, science.howstuffworks.com/transport/engines-equipment/maglev-train.htm. 

“Magnetic Resonance Imaging (MRI).” Johns Hopkins Medicine, 29 Aug. 2023, www.hopkinsmedicine.org/health/treatment-tests-and-therapies/magnetic-resonance-imaging-mri#:~:text=The%20strong%20magnetic%20field%20created,and%20send%20back%20radio%20signals. 

“Magnetic Resonance Imaging (MRI).” National Institute of Biomedical Imaging and Bioengineering, U.S. Department of Health and Human Services, www.nibib.nih.gov/science-education/science-topics/magnetic-resonance-imaging-mri. Accessed 29 Feb. 2024. 

“Atomic Nuclei: Larmor Precession Frequency.” Protocol, www.jove.com/t/12985/atomic-nuclei-larmor-precession-frequency#:~:text=The%20precession%20of%20the%20magnetic,applied%20magnetic%20field%2C%20B0. Accessed 29 Feb. 2024. 

“Radiofrequency Pulse.” Radiofrequency Pulse - an Overview | ScienceDirect Topics, www.sciencedirect.com/topics/medicine-and-dentistry/radiofrequency-pulse. Accessed 2 Mar. 2024. 

“How MRI Works - Part 1 - NMR BASICS.” YouTube, YouTube, 26 Aug. 2018, www.youtube.com/watch?v=TQegSF4ZiIQ. 

“Quantum Computers Explained – Limits of Human Technology.” YouTube, YouTube, 8 Dec. 2015, www.youtube.com/watch?v=JhHMJCUmq28. 

“What Is Quantum Computing?” IBM, www.ibm.com/topics/quantum-computing. Accessed 4 Mar. 2024. 

“Creating the Heart of a Quantum Computer: Developing Qubits.” Energy.Gov, www.energy.gov/science/articles/creating-heart-quantum-computer-developing-qubits. Accessed 8 Mar. 2024. 

“Quantum Computers, Explained with MKBHD.” YouTube, YouTube, 4 Apr. 2023, www.youtube.com/watch?v=e3fz3dqhN44. 

News Center, and Lindsey Valich. “A Quantum Leap in Cooling Atoms for Better Computers.” News Center, 22 Sept. 2023, www.rochester.edu/newscenter/quantum-mechanics-thermoelectricity-superposition-entanglement-565852/#:~:text=Quantum%20computers%20require%20cold%20environments,information%20contained%20in%20the%20qubits. 

“Quantum Computing Chips: A Complete Guide.” SEEQC, seeqc.com/blog/quantum-computing-chips#:~:text=A%20quantum%20computing%20chip%20serves,0%2C%201%2C%20or%20both. Accessed 8 Mar. 2024. 

Ballon, Alvaro. “Trapped Ion Quantum Computers.” PennyLane Demos, Xanadu, 1 Jan. 2024, pennylane.ai/qml/demos/tutorial_trapped_ions/. 

“Quantum Computing Hardware - An Introduction.” YouTube, YouTube, 2 Dec. 2021, www.youtube.com/watch?v=0xMX8mSeIKw. 

Ballon, Alvaro. “Photonic Quantum Computers.” PennyLane Demos, Xanadu, 1 Jan. 2024, pennylane.ai/qml/demos/tutorial_photonics/. 

“New Quantum Computers - Potential and Pitfalls | DW Documentary.” YouTube, YouTube, 12 Mar. 2024, www.youtube.com/watch?v=0HFzTYlhT2E.

Stone, Kristin. “About Animal Testing.” Humane Society International, 6 July 2023, www.hsi.org/news-resources/about/.

I would like to thank my science teacher M. Abbott for helping me throughout the researching process and supporting me on my learning journey. I would also like to thank my coordinator for allowing me to join the fair, and all my friends for tolerating my sometimes incoherent ramblings due to my new knowledge.

I would like to especially thank the following theoretical and quantum physicists and educators, whose words I referred back to the most during this project.

Dominic Walliman (PhD for quantum physics), for being the one to convince me picking this topic was the right choice

Derek Muller (PhD for physics education research), for teaching me about spooky action at a distance and being as excited about it as I was

David Tong (Cambridge professor and theoretical physicist), for making quantum field theory my favorite theory concerning quantum physics yet

And, last but not least, Carlo Rovelli (PhD for theoretical physics), for his luminous descriptions of quantum physics in his novel "Helgoland: Making Sense of the Quantum Revolution" and keeping me entertained the whole way through.