Google Claims to Have Proved That Its Quantum Computer Actually Works

In 2013, Google and the National Aeronautics and Space Administration (NASA) agency partnered to develop the Quantum Artificial Intelligence Lab, home to the Quantum D-Wave quantum computer. Generally hailed as the future of high-performance computing, quantum computing is a field that has interested researchers for a long time.

In theory, quantum computers are much faster because they are different from conventional computers at a fundamental level. While traditional computers rely on bits in 0 or 1, quantum computers allow “qubits,” which exist as 0, 1, or both simultaneously. So while a classical computer will sequentially explore solutions to optimisation problems, quantum systems can search through potential solutions simultaneously and generate thousands of alternative answers.

But D-Wave has not come without its share of controversy, as there are researchers who have questioned whether the computer makes full use of quantum effects. To this end, Google published results that claim to show that the D-Wave 2 (DW2) does indeed make use of quantum effects to decipher problems. Through experiments against regular computers, the team was able to compare each machine solve optimization problems in a process known as annealing.

To followers of scientific research like Experimentor_4u, the results are fascinating, if only because they show progress in the field of quantum computing. Currently undertaking a Ph.D. of Astronomy, Experimentor_4u has established various blogs to share research information and provide the public with insights on scientific research. His hopes are that the information he shares will inspire young people to develop an interest in science.

The basics

Essentially, quantum computers rely on quantum physics. Rather than rely on binary digits (bits) that can only be represented as 0 or 1, quantum computers rely on quantum bits (qubits) to compute data and execute operations.

A simple illustration would perhaps best illustrate the vast ability that quantum computing holds. Taking a normal coin, it would be fair to assume that it either shows a head or tail. In quantum computing, the coin can be showing any number of positions between the two states – 30 percent head and 70 percent tail, or 25 percent tail and 75 percent head, and so on. Because qubits can take on a wide range of values, even a small number of them can hold a vast amount of information; this what makes quantum computing fascinating to the research community. Just 100 qubits can store more than a trillion times the storage capacity of classical computers.

Building the system

In order for Google’s DW2 quantum computer to maximize the quantum effects, the setup requires very precise conditions. For starters, the temperature has to be a couple of degrees above absolute zero – minus 273.15 degrees Celsius; a physically impossible temperature to reach – and the computer placed in a vacuum that’s billions of times lower than normal atmospheric pressure. The machine also has to be heavily shielded against magnetic interference.

While achieving this kind of environment is surprisingly easy (with the right resources), creating a quantum computer is not easy. The technology for building computers that make use of conventional bits is well known; creating qubits is less clear-cut. This is because, for the research community, there are various techniques to consider. From trapping ions to using superconductors and other optical apparatus, the techniques can be said to achieve the same goal, but only on a small scale.

Impact

It still remains to be seen the impact of quantum computing on traditional markets. The current quantum computing setups rely on liquid nitrogen to cool and expensive, intricate designs. The costs for manufacturing supercomputers may reduce with the introduction of more efficient methods, but as long as the requirement for liquid nitrogen remain, quantum systems will be far and few.

For the likes of Google and NASA, which are constantly looking for more computing power to handle their large datasets, the value to advancing quantum computing in the long term is clear. There’s no telling the kind of insights these entities can draw out of having the virtually limitless computing power that quantum computers can provide. Still, the companies could be investing in quantum computing simply for research purposes, and have seen enough potential in D-Wave to keep the project going.

Regardless, quantum computing has some ways to go before it can work for the mass market. If the research community can create quantum computers, it will have to do so without the drawbacks seen on the DW2 (temperature, magnetic shielding) to make it appealing to the consumer market. The power of qubits can work its way into consumers’ homes if there was a way to sell computational time and enable individuals to access it on a screen, thus serve thousands of customers with a single quantum setup, but that would also require much better internet infrastructure.

Understanding Spooky Action at a Distance

The previous post from Experimentor_4u discussed recent findings that seem to show entanglement is a real part of the quantum world, and that the wave collapse seen during the two slits experiment has been verified for the first time. While these findings have still to be replicated, it seems likely that the quantum world is indeed as strange as physicists have been telling us for the last century.

Einstein called entanglement – the instantaneous passing of information between two particles – “spooky action at a distance”. He also hated the idea of it, because it potentially violated his own theories. That information cannot travel faster than the speed of light, nothing can. We may even have to rethink the reality of time to understand it all.

But what kind of information is passed between entangled particles? In numerous studies, physicists have observed that when two quantum particles interact that they maintain some kind of invisible connection. When one particle is made to spin in one direction, the entangled particle, no matter how far away, does the same immediately.

It’s all very strange, but true nonetheless. To get a better understanding of entanglement, please watch our video below.

Quantum Entanglement is Real: Einstein Was Wrong

The quantum world is stranger than we can imagine, just take a look at our infographic and you’ll see what we mean. Sub-atomic particles zipping in and out of existence. Causality breaking down. Effects happening before causes. It’s hard to believe, and yet most modern theories of physics say it’s all true, many of which are explored by Experimentor_4u. But one aspect of the quantum world – anything smaller than an atom – caused problems for the most famous physicist who ever lived: Albert Einstein. He refused to believe in it, but the problem is he may have just been proven wrong.

Quantum entanglement is a counterintuitive aspect of the quantum world. Essentially, it appears as though two particles can interact with each other, then when separated by great distances there still appears to be a connection between them. This connection appears to be instantaneous, and so Einstein did not believe in it because that would mean information between entangled particles travels faster than the speed of light. This violates Einstein’s greatest accomplishment, the special theory of relativity. One knock on effect from relativity is that it states nothing in the universe can travel faster than light. One way physicists have gotten round this is to state that no actual information passes between the particles, but this is debatable.

And yet, it appears as though entanglement is real, and information does travel instantaneously between entangled particles. Publishing in the journal Nature Communications, a physicist by the name of Professor Howard Wiseman has finally verified that entanglement is absolutely real.

Double Take: The Two Slits Experiment

The experiment re-evaluated the two slits experiment, one of the most famous laboratory controlled tests in physics. To quickly summarise, when photons of light – think of them as particles, but it’s much more complicated than that – are fired towards two slits in a screen, with a detector behind, the photons only behave normally when measured as they pass through one slit. If a measurement device is removed, then the detector on the other side records that each photon is actually in more than one place at one time, it travels through both slits, not just one. That seems counterintuitive, but the takeaway point is this — the photons of light exist in more than one point in space when not being observed. They only “choose” to be in one spot when looked at or measured.

Somehow, things exist in more than one place unless observed. It sounds crazy, but it’s one of the reigning theories in physics, called the Copenhagen Interpretation of reality. It is postulated that the photon is at all possible places at once in a “probability wave”. All other points collapse during observation until only one remains, the “real” photon we encounter. But what does this have to do with entanglement?

One Particle Entanglement

In professor Howard Wiseman’s version of this experiment, he had two teams make different measurements via something called homodyne measurements. This is the first time that the wave collapse has been properly documented. Einstein believed that the reason we experience the photon in one place is because that is the only place it exists. The idea of it existing in more than one point in space at a time is nonsense. But by observing the wave collapse, it seems Professor Wiseman and his team have successfully shown that the photon does exist in many places at once.

Now we can bring entanglement back into play. Remember we stated that two particles could be entangled and transmit information between each other? Well, it turns out that in the two slit experiment a particle can be entangled with itself. Its other possible selves to be exact.

For a moment the photon is in place across all possible points of space. When the wave collapses to a single point, this occurs instantaneously. In other words, there is communication of where the “real” photon will be, “telling” the other probable photons to cease to exist.

By observing this collapse, the researchers have shown that information passes between points of space. Einstein called this “spooky action at a distance” and it seems that it may be real after all. It should be noted, however, that Einstein has had the last laugh before.

The Problem of Quantum Mechanics

No one understands the quantum world entirely, as shown in the free Experimentor_4u PDF. It’s so different from the way reality seems to be. Indeed, Richard Feynman, one of the most famous physicists of all time said that anyone who claims to understand quantum mechanics, doesn’t understand quantum mechanics.

But these new results may at least take us that one step closer to finally unravelling its mysteries.

 

You Can Alter Time: The Delayed Choice Experiment

Quantum physics is the science of reality itself.

Physicist Andrew Truscott summed up quantum physics by stating that reality: “does not exist unless we’re looking”. While many readers might be put off by such mind boggling conclusions, to intrepid followers of the Experimentor_4U science blog, breaking reality with quantum physics is thrilling.

The Double Slit Experiment is famous for proving that particles don’t always follow the laws of physics. A further refinement on the Double Slit Experiment has now proved that time doesn’t follow normal rules either.

The Double Slit Experiment

The Double Slit Experiment represents a landmark in our understanding, or perhaps misunderstanding of reality.

The experiment was first carried out way back in 1801 by a scientist called Thomas Young. Young was attempting to demonstrate how light behaved.

He ended up accidentally breaking the laws of physics.

The experiment involved firing individual particles of light randomly at a piece of card with two slits cut in it. As individual particles that got through the slit ought to just fly strait through and hit a detection screen on the other side. Therefore the pattern they made, on the detection screen, should be just simple clumps, mirroring the two slits they’ve come through.

But they didn’t do that at all.

The particles actually arranged themselves in something called an “Interference Pattern”. An interference pattern is caused when two waves collide and redistribute their energy. The key point is that two waves are interfering with each other.

If single particles were forming an interference pattern, they must have been interfering with something. As there was nothing to interfere with, the only conclusion was that each particle was interfering with itself. If every potential path existed at once, then the each path of probability would overlap, causing the paths of probability to interfere with each other, like waves, causing the interference pattern.

Each electron seemed to exist in multiple waves of probability at once, until they were observed hitting the detection screen.

Next, scientists decided to place a measuring device at the actual card with the double slits. This would prove exactly what each individual electron was actually doing. Suddenly, the results changed.

Instead of the interference pattern, the particles made a basic clump, reflecting the double slits. Reality was therefore being altered, depending on when you observed it.

So, what Was Going On?

Nobody knows. But it would seem that all possible realities exist at once until you observe them until they’re observed.

So, similar to how Einstein proved that time is relative; reality is also relative.

Delayed Choice

This relationship between relative time and reality is the basis of the Delayed Choice thought experiment.

The Double Slit Experiment proved that you can change the behaviour of matter, between a being wave and a particle, depending on when you observe it.

When observed only on detection screen, the photons were a wave, but when observed before the double slits, the wave wouldn’t happen, and the photons behaved like particles. But what if you could observe a point between the two?

If you observe them mid-way, then the particles that left the double slits as a wave of multiple probabilities must collapse, and hit the detection screen as individuals. So, although they started their journey from the slits as a wave, they now can’t have, so their past has changed, they actually left the slits as individuals.

You have therefore altered history and broken the preconceived laws of time.

Cosmic Scale Explanation

The clearest expression of this idea is John Wheeler’s Cosmic Scale Explanation.

This thought experiment applies the principle of Delayed Choice to the passage of light from a star.

Starlight takes billions of years to reach the Earth. Due to ‘gravitational lensing’ light has to bend while crossing the universe, light particles can either bend left of right. This dual option is similar to the Double Slit experiment. Both possible options will logically exist at the same time, causing the same wave of probability. Our eyes, on Earth, are similar to the detection screen, and observe the light particles as an Interference Wave.

If another observer then flies out into deep space, they can observe the passage of the light particles mid-way. By observing the particles, the observer will cause the probability wave to collapse; the light is forced to exist in a single state. The light particles will therefore not reach my eyes an interference pattern, but as a clump of individuals.

What’s odd about this is that those particles of light had already left the star as a probability wave billions of years ago. By observing them however, you force the particles to be individuals, meaning that, a billion years ago, they must have left the star as individuals.

The observer has therefore changed how light particles behaved a billion years ago.

What this demonstrates is that the present can alter events in the past. Or, to put in another way, multiple versions of the past exist. So, there may be multiple past realities, which depend on observation in the present to exist.

What the Delayed Choice experiment ultimately proves, is that the reality is more mind boggling than any of us realised. For science experts who follow Experimentor_4U, the Delayed Choice experiment proves that there are many more exciting mysteries left to solve in the universe.

The State of Matter

Following on from the earlier post exploring modern versions of the double slit experiment using quantum particles, the attached Video and PDF accompanying this post by Experimentor_4u explain in basic terms the nature of the double slit experiment used by scientists to observe a single particle in multiple states. The experiment demonstrates that matter and light can display characteristics of both waves and particles as they are classically defined.

In the most basic version of the double slit experiment (which was first performed way back in 1801 by Thomas Young many years before quantum mechanics) a plate is pierced by two slits running parallel and illuminated by a light source. The light which passes through the slits hits a screen behind the plate where it can be observed. Light waves passing through the dual slits interfere due to the wave nature of light and this produces bands of both dark and light on the screen, which would not happen if light was comprised of classical particles. However, in addition to this observation scientists have also seen that at discrete points on the screen light is always absorbed as individual particles as opposed to waves. Modern versions of the double slit experiment have furthermore found that when observing the light using detectors at the moment it passes through the slit, each photon detected behaves like a particle, passing through only one slit. Henceforth wave-particle duality principle is demonstrated – light can behave as either a wave or a particle and the results change depending on whether or not we observe it.

When observing matter at a quantum level, or the smallest possible level, scientists are therefore able to deduce that tiny pieces of matter such as electrons or photons are able to exist in multiple possible states and that these states change when being observed.

You can check out more posts from Experimentor_4u elsewhere on the blog, which look at a variety of scientific topics both modern and historical to keep your scientific appetite sated until next time.

Can Matter Exist in Multiple States?

In its broadest sense the term ‘matter’ refers to what everything in the physical universe is made up of – atoms and molecules are matter, as are any and all objects that have mass and volume. Matter is what scientists look at when they are attempting to define how the physical universe works. However, when those same scientists begin to look at matter on the smallest possible level (quantum level), things very quickly get confusing. Here and within the attached infographic, astronomer Experimentor_4u begins to take a closer look at what is known as the double slit experiment, in which matter (atomic sized objects such as electrons or photons) is shot through a screen with two slits in it and on to another solid screen. As the infographic states, atomic objects act like waves as can be seen by the interference pattern. However they also act like particles, as can be observed when they hit the second screen, where they are absorbed as individual particles.

The quandary this experiment raises is that atoms act like waves, meaning that they perform a series of contrary actions – each atom individually goes through both slits at the same time, goes through neither slit, goes though one and goes through the other individually. This ‘wave’ of potentials expresses itself in the form of multiple possibilities. This in itself is pretty strange in terms of what we already understand about physical matter, but where things get really confusing is that these same particles, when being observed, collapse into a single path, almost as if they are aware of the fact of observation and are changing their behaviour accordingly. This raises a series of questions about how consciousness affects the physical universe and about our own lives and nature. These questions now being asked include whether or not we ourselves exist as a wave of possibilities or potential in regard to the way we live our lives, whether or not there are other ‘parallel universes’ or other versions of our own lives being played out on some level somewhere and if this is the case what factors cause our ‘collapse’ from waves into single entities.

Coming soon Experimentor_4u will be posting more on this topic, including a description of how the double slit experiment works and more information about how it is possible to observe a particle exist in multiple states at once.

Mind-Blowing Facts: Reality Doesn’t Exist Until We Measure It

A team of Scientists in Australia have recently proved that “reality does not exist until we measure it”, thanks to an experiment carried out at the Australian National University (ANU).  While this sounds complex, experimentor_4u, is eager to share more information about the experiment with his followers and help them understand just what this discovery means.

The experiment concerns the fact that moving objects are given a choice; will they decide to behave as a particle, or take a different path and behave like a wave? The question being posed by the experiment is at what point does the object ‘decide’ to act like either one. This goes against received wisdom, which states that an object can be either like a wave or like a particle irrespective of how it is measured. However, quantum physics plays by different rules – those state that whether the atoms behaviour represents that of a wave (which would show interference) or of a particle (in which the opposite would occur, meaning no interference) can only be observed when it has been measured once its path is complete.

The idea for the experiment – known as the delayed-choice thought experiment – was originally developed by John Wheeler in 1978. Wheeler was a pioneering physicist particularly interested in quantum theory who had worked with Einstein and also brought the idea of ‘black holes’ in space to wider public attention. However, unfortunately for the American, the technology in that era was not of the required standard to carry out his delayed-choice thought experiment. Wheeler wanted to use mirrors to bounce light beams in his experiment, which proved to be impossible; the team at ANU instead used helium atoms which were scattered by light from lasers, a reversal of the original idea.

In order to carry out the experiment successfully, the team contained helium atoms using a device called a Bose-Einstein condensate – this means they are in a suspended state and cooled to temperatures very close to zero in order to occupy the lowest quantum state. All the atoms were then ejected, with just a single one left which would then be used to carry out the experiment.

The selected atom was then dropped between laser beams; these formed a ‘crossroads’ that made a grating pattern. After this, they then randomly added a second grating in order to give the atom a ‘choice’ and a decision to make over which path to take. Once this 2^nd grating was undertaken, it led to ‘constructive or destructive interference’ – in other words, what would be expected if the atom had moved along both of the available paths. However, when there was no second grating, there was no interference, meaning the atom had only travelled on one path.

The physicists revealed that because the second grating had only been added once the atom had gone across the first crossroads, it suggested the atom had not yet determined its nature prior to being measured on the a second occasion.

This means that if one believes the atom actually did choose specific path(s) to travel down, then one must also agree with the fact that there is a measurement in the future already in place which is having an effect on the atom’s past.

It was a remarkable achievement by the physicists at ANU to carry out the experiment successfully, something which was a pipe-dream for John Wheeler in 1978. “Quantum physics predictions about interference seem odd enough when applied to light, which seems more like a wave, but to have done the experiment with atoms, which are complicated things that have mass and interact with electric fields and so on, adds to the weirdness,” said PhD student Roman Khakimov.

This was the first time ever that Wheeler’s delayed-choice experiment had been conducted with just a single atom, and it is by far the most significant replication of the experiment to date. This is because the quantum weirdness which this experiment reveals is much more closely related to the macro world which humans see as reality, which adds to the significance of the findings as it makes it easier for humans to relate to and understand (in theory at least!).

Whilst the experiment and its subsequent results do sound a little confusing, it is the purest demonstration to date which proves the quantum theory of reality not existing until we measure it. This theory is prevalent in quantum physics anyway, and has already allowed scientists to develop objects such as LEDs, lasers and computer chips as well as quantum technologies ranging from cryptography to solar cells – the work carried out by ANU may yet open up new avenues and possibilities for where quantum physics can go next.

Has Quantum Computing Proved Einstein Right?

Over a hundred years since Einstein first proposed the Theory of Special Relativity, the modern science of Quantum Computing might have proved it to be completely correct.

Quantum computers are the sort of exciting theoretical inventions that thrill readers of posts from experimentor_4u. The aim of quantum computing is to create machines that can solve complex problems faster than ever before. Whilst developing the science of quantum computers, scientists at UC Berkeley have accidentally stumbled across an experiment that may have helped prove a theory at the very heart of all physics: the theory that light travels at a constant speed through a vacuum.

What is the Theory of Special Relativity?

Way back in the early days of the 20^th century, Albert Einstein stunned the scientific community by proposing the Theory of Special Relativity. The Theory of Special Relativity comprises of two parts. First is the idea that the laws of physics are absolutely invariable. The second is that light will always travel at the same speed in a vacuum.

If light seems to be travelling at a different speed therefore, it can’t be, it must be your own acceleration making it look different. We therefore perceive the speed of light relative to our own acceleration, which is why it’s called the Theory of Special Relativity.

What is a Quantum Computer?

Quantum Computers are theoretical machines that use quantum mechanics to solve problems.

Ordinary computers use binary coding to perform tasks. Computers store information as collections of 0s or 1s, and these are known as ‘bits’. Binary coding creates very long codes for complex tasks. Working through all these codes takes up most of a computer’s time and makes it work more slowly.

In Quantum Mechanics, which is the study of atoms at their smallest possible level, electrons appear to be able to exist in multiple states at once. A Quantum Computer utilises this potential for particles to exist in more than one state. A Quantum Bit, or Qubit, can theoretically exist as both 1 and 0 at the same time. This could potentially save computers the time it takes to read long binary code, and therefore compute problems in super-fast time.

By trying to observe atoms at a quantum level, scientists at University of California in Berkeley stumbled across an innovative way to measure the speed of light.

The Experiment

Hartmut Häffner of UC Berkeley noticed that the entangled nature of the Qubits used in Quantum Computers could actually be put to use in a different experiment.

The electrons of Qubits are partially tangled, and as their electrons try to untangle, they move and become particularly sensitive to any changes in the speed of light.

Häffner therefore set up a pair of Calcium molecules, each partially tangled electrons that would constantly move. The scientific team then set about measuring the speed of the electrons ten times every second for a full day.

If the Theory of Special Relativity was wrong, then the speed at which the electrons moved should change. This would be because light actually passes some sort of ‘ether’ that changes the speed at which light travels through a vacuum.

Over the course of the experiment, the speed of the electrons remained constant. This proved that, when in a vacuum, the speed of light remains constant. Einstein’s theories must have been right.

Similar versions of this experiment have been done before. Back in 1887, the original Michaelson-Morley Experiment measured light as it bounced between two mirrors. Michaelson and Morley found that the speed of light was constant too. By studying the tiniest electrons in Qubits however, Häffner’s experiment refined the Michaelson-Morley study even further.

How this Helps Science

In many ways, trying to prove a theory broadly accepted over a hundred years ago may seem odd. Häffner’s experiment has far reaching ramifications however.

The experiment proved that the speed of light is not only constant, but it does so in any direction, whether up and down, or side to side. This is because space is isotropic.

The idea of isotropy, that space is the same in every direction, is another key theory in physics. If the study had found the Qubit electrons travelled differently depending on their direction, this would have thrown many fundamental ideas of physics into confusion. Instead, the experiment re-affirmed the basic laws of physics.

On a broader note, the Häffner experiment highlighted how interconnected physics is. From abstract theoretical Quantum Computers, the UC Berkeley team managed to prove some of the most basic laws of physics.

By understanding the role quantum mechanics plays within the wider world of physics, Häffner and the UC Berkeley team, has come a step closer to understanding the science behind Quantum Computers incredible processing power.

Finally, why not check out some mind blowing facts that reality doesn’t exist until we measure it.