Quantum Supremacy: How the Quantum Computer Revolution Will Change Everything

by Michio Kaku

For example, the “IBM Q Experience,” launched in 2016, makes fifteen quantum computers available to the public via the internet for free.

“In principle, quantum will be relevant for all CIOs as it will accelerate solutions to a large range of problems.

Those companies need to become owners of quantum capability.”

Back in 2012, when physicist John Preskill of the California Institute of Technology first coined the term “quantum supremacy,” many scientists shook their heads.

Documents leaked by whistleblowers have shown that the CIA and the National Security Agency are closely following developments in the field. This is because quantum computers are so powerful that, in principle, they could break all known cybercodes.

NIST has already announced they expect that by 2029 quantum computers will be able to break 128-bit AES encryption, the code used by many companies.

Moore’s law states that computer power doubles every eighteen months.

As Intel’s Sanjay Natarajan has said, “We’ve squeezed, we believe, everything you can squeeze out of that architecture.”

“There’s Plenty of Room at the Bottom” and subsequent articles, he asked: Why not replace this sequence of 0s and 1s with states of atoms, making an atomic computer? Why not replace transistors with the smallest possible object, the atom?

The fact that, at the atomic level, objects can exist simultaneously in multiple states is called superposition. (This also means the familiar laws

of common sense are routinely violated at the atomic level. At that scale, electrons can be in two places

In addition, these qubits can interact with each other, which is not possible for ordinary bits. ...

In order for quantum computers to work, atoms have to be arranged precisely so that they vibrate in unison. This is called coherence. But atoms are incredibly small and sensitive objects. The smallest impurity or disturbance from the outside world can cause this array of atoms to fall out of coherence, ruining the entire calculation. This fragility is the main

problem facing quantum computers. So the trillion-dollar question is: Can we control decoherence?

without a problem. For example, the miracle

Mother Nature does not use a roomful of exotic devices operating at near absolute zero to execute photosynthesis. For reasons

that are not well understood, in the natural world coherence can be maintained even on a warm, sunny day, when disturbances from the outside world should create chaos at the atomic level.

The key bottleneck for the Solar Age is often overlooked; it is the battery. We have been spoiled by the fact that computer power grows exponentially fast, and we unconsciously assume that the same pace of improvement applies for all electronic technology.

But the problem of converting light into sugar is a quantum

mechanical process.

to identify genes like BRCA1 and BRCA2 that can likely result in breast cancer.

So the protein folding problem is one of the greatest, uncharted areas in biology.

itself. But precisely how a protein molecule folds up is beyond the capability of any conventional computer.

Is mathematics complete? Do the rules of mathematics ensure that every true statement can be proven, or are there true statements that can elude the most exceptional minds of the human race because they are, in fact, not provable?

In 1931, at a conference where Hilbert was discussing his program, a young Austrian mathematician, Kurt Gödel, proved it was impossible.

Alan Turing: Computer Science Pioneer

of computation, allowing the entire field to be put on a firm mathematical basis. Today, Turing machines are the foundation for all modern computers. Everything, from the giant supercomputers of the Pentagon to the cell phone in your pocket, are all examples of Turing machines. It is no exaggeration to say that almost all of modern society is built on Turing machines.

Are there true statements that cannot be computed in a finite amount of time by a Turing machine, given a set of axioms? Like the work of Gödel, Turing showed that the answer is yes.

So far, no machine has been able to consistently pass the Turing test.

So mathematicians would focus on a different question: Is it possible to build a quantum Turing machine?

Today, Schrödinger’s wave equation is the bedrock of the quantum theory, taught in any graduate course in advanced physics. It forms the heart and soul of

Physicist Max Born lit the fuse of this explosion by postulating that matter consists of particles, but the probability of finding that particle is given by a wave.

world, it means that everything we know

wrong. For example: We

All the miraculous electronic devices in your living room are possible precisely because

electrons can perform these fantastic tricks.

No, although the information that traveled between the two electrons was instantaneously transmitted, it was also random information, and hence useless. This means you cannot send useful codes containing a message faster than light using the EPR experiment. If you actually analyze the EPR signal, you only find gibberish. So information can travel instantly between coherent particles, but useful information that carries a message cannot go faster than light.)

Today, this principle is called entanglement, the idea that when two objects are coherent with each other (vibrating in the same way), then they remain coherent, even if separated by vast distances.

How small can you make a computer?

size of atoms. In fact, he conjectured, the next frontier for physics could be to create machines as small as atoms, pioneering a growing field now called nanotechnology.

He summarized his idea for quantum computers by saying, “Nature isn’t classical, dammit, and if you want to make a simulation of nature, you’d better make it quantum mechanical.”

saying that the goal of every physicist “is to prove yourself wrong as soon as possible.” In other words, swallow your pride and admit that what you are doing may be a dead end, and prove it as soon as possible so you can move on to the next idea.

The teacher noted that if a ball rolls down a hill, there are an infinite number of ways it can possibly roll, but there is only one path that it actually takes. How does it know which path to take?

calculate what is called the action. (The action is similar to the energy of the system. It is the kinetic energy minus the potential energy.)

This is now called the path integral approach, because you are adding up contributions from all the paths an object can take. Much to his shock, he found he could derive the Schrödinger equation.

David Deutsch takes these mind-boggling concepts seriously. Why are quantum computers so powerful? he asks. Because the electrons are simultaneously calculating in

parallel universes. They are interacting and interfering with each other via entanglement. So they can quickly outrace a traditional computer that computes in only one universe.

But the work of Peter Shor at AT&T in the early 1990s changed everything.

The leading code for secret transmissions is called the RSA standard and is based on factoring a very large number. For example, start with two numbers, each 100 digits long. If you multiply them together, you can get a number approaching 200 digits. Multiplying two numbers is an easy task. But if someone gave you this 200-digit number to start with, and asked you to factorize it (find

the two numbers that multiply together to make it), it might take centuries or more to do this with a digital computer. This is called a trapdoor function.