C&B Notes

A Quantum Leap?

Quantum computers have been a promise of the future for decades.  Claim by Google of a recent “quantum supremacy” breakthrough has been disputed by other tech giants who are also trying to push the field forward, but we are now on the verge of the quantum age.  Bell Labs created the first working transistor in 1947.  Will advances in quantum computing be just as significant?

Google said on Wednesday that it had achieved a long-sought breakthrough called “quantum supremacy,” which could allow new kinds of computers to do calculations at speeds that are inconceivable with today’s technology. The Silicon Valley giant’s research lab in Santa Barbara, Calif., reached a milestone that scientists had been working toward since the 1980s: Its quantum computer performed a task that isn’t possible with traditional computers, according to a paper published in the science journal Nature. A quantum machine could one day drive big advances in areas like artificial intelligence and make even the most powerful supercomputers look like toys. The Google device did in 3 minutes 20 seconds a mathematical calculation that supercomputers could not complete in under 10,000 years, the company said in its paper. Scientists likened the announcement by Google to the Wright brothers’ first plane flight in 1903 — proof that something is really possible even though it may be years before it can fulfill its potential.

A quantum machine, the result of more than a century’s worth of research into a type of physics called quantum mechanics, operates in a completely different manner from regular computers. It relies on the mind-bending ways some objects act at the subatomic level or when exposed to extreme cold, like the metal chilled to nearly 460 degrees below zero inside Google’s machine. One day, researchers believe, these devices could power advances in artificial intelligence or easily overwhelm the encryption that protects computers vital to national security. Because of that, the governments of the United States and China consider quantum computing a national security priority.

But first, scientists must prove such a machine can become more than a project that hints at what could eventually be possible. Traditional computers perform calculations by processing “bits” of information, with each bit holding either a 1 or a 0. That has been the case for decades. Understanding how a quantum computer is different requires a philosophical leap: accepting the notion that a single object can behave like two separate objects at the same time when it is either extremely small or extremely cold. By harnessing that odd behavior, scientists can instead build a quantum bit, or qubit, which stores a combination of 1 and 0. Two qubits can hold four values at once. And as the number of qubits grows, a quantum computer becomes exponentially more powerful.

Scientists first described the idea in the 1980s, but qubits are fragile. Stringing even a few together can involve years of work. For the past several decades, labs in academia, industry and government have worked on quantum computing through a wide variety of techniques, including systems built around particles of light or electromagnetic fields that trap tiny charged particles. About 20 years ago, researchers in Japan pioneered “superconducting qubits,” for which certain metals are chilled to extremely low temperatures. This method has shown particular promise, sparking projects at IBM, Google and Intel. Their machines look nothing like a regular computer. They are large cylinders of metal and twisted wires that are dropped into stainless steel refrigerators. You send information to the machine, as you would to a traditional computer chip, and receive calculations in return.

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