The Mountain View giant said the journey would begin that day with the unveiling of its new Quantum AI campus in Santa Barbara, Calif. (above, photo: Google). The campus will house Google’s first quantum data center, its quantum hardware research laboratories, and a quantum processor-chip fabrication facility. Officials said they expect to reach the goal of a commercial quantum computer in 2029 or earlier.
On Google’s company blog, Erik Lucero explained: “To reach this goal, we’re on a journey to build 1,000,000 physical qubits that work in concert inside a room-sized error-corrected quantum computer. That’s a big leap from today’s modestly-sized systems of fewer than 100 qubits.” Qubits are the information bits that replace the conventional plus-or-minus bits used in classical computers. A qubit can be in a plus or minus state, or both, simultaneously (a quality called superposition), and it also has the unique ability to connect, interact, and travel with other qubits at distances that can be substantial (a process called entanglement).
In describing possible practical uses for their quantum computers, Lucero included several fields, including chemistry, medicine, and materials. And he explained what is perhaps the most essential quality of quantum for researchers. “Nature is quantum mechanical: The bonds and interactions among atoms behave probabilistically, with richer dynamics that exhaust the simple classical computing logic.”
To understand and make use of how molecules and matter really work, you need to enter their level or at least accurately model what happens there. Quantum computers have that kind of extended reach. We’ve so far been satisfied with modeling our problems with binary bits that use the + - logic of classical computing. Quantum computing has the potential for mathematically simulating the universe that’s around us and where that will lead, especially in fields like molecular medicine, in almost unimaginable ways.
NEW MILE MARKERS
Until recently, the holy grail for those on this journey has been something called “quantum supremacy.” Quantum supremacy is the ability to demonstrate that a programmable quantum device can solve a problem that no classical computer can solve in any feasible amount of time (Wikipedia). On October 23, 2019, Google published the result of a head-to-head contest in Nature, which the company claimed established quantum supremacy. The problem involved verifying part of a prime number experiment, and it was attempted by Google’s Sycamore quantum computer and the Summit supercomputer at Oak Ridge National Laboratory in Tennessee.
At the time, Summit was the world’s leading supercomputer, able to perform 200 million billion floating-point operations per second with 40,000 processor units and 250 million gigabytes of storage. Sycamore had 53 working qubits in its system. The final score: Sycamore solved the problem in 200 seconds, and the Summit couldn’t complete it unless it had an additional 10,000 years to calculate.
The title quantum supremacy has since been scaled down to “quantum advantage” with the practical realization that single solutions don’t benchmark an entire system. And along with this return to reality, it’s become obvious that future computing systems will be a hybrid of classical and quantum—one won’t replace the other.
Also, the oversimplification of the number of qubits serving as a scoring system, synonymous with the overall value and power for a system, has also lost some of its significance. Potential horsepower isn’t performance. Qubit counts can be a rough indicator of progress, but not a lot more. Today, the leaders are Google with a 72-qubit machine, IBM with 65, Honeywell 64, and China has a reported 63 qubits on one of their machines. IBM has already predicted that it will have a 1,121-qubit computer by 2023. As important as the number of information bits are in a system, equally significant is how “noisy” (error-prone) or error-correcting these qubits are.
ROADS NOT TAKEN
In order to control the subatomic particles functioning as qubits in their computers, Google has had to deal with maintaining the difficult physical environment of near absolute zero to slow the qubits to some kind of stability. This requirement of housings for -460 degrees Fahrenheit is difficult, expensive, and likely never to be scaled down to desktop size. IBM is following this same path for their quantum computers.
There is, however, another road that could lead to quantum computers that operate in more practical environments. In September 2020, the Toronto-based Xanadu Quantum Technologies announced that businesses could now have access to the first commercially available photonic quantum computers through its Xanadu Quantum Cloud platform. A photonic quantum machine utilizes single light particles (photons) that can be programmed on quantum computers, like Xanadu’s, that run at room temperatures.
NOT THEN, NOW
A point repeatedly made by many of the presenters and panelists at the recent Inside Quantum Technology conference in New York City (May 17-20, 2021) was that quantum computing isn’t on the way; it’s here right now. You can contract for time on quantum computers with a number of companies to solve particular problems that your systems can’t solve.
Amazon’s cloud networks now include Amazon Braket, a quantum service for researchers and developers. Honeywell and IBM have commercial services available today, and there are numerous academic installations around the world that offer access to both quantum and supercomputers for those doing research and testing. For students in the United States, IBM offers help for those who want to learn Qiskit, the company’s open-source software development kit for quantum programs that the students can write and test on IBM’s online quantum processors.
Along with quantum computers, there are numerous quantum sensors available today including atomic clocks, magnetometers, and pressure and temperatures gauges. These devices measure very small changes in an environment by using entanglement dynamics. Regarding security, companies like Swiss-based ID Quantique and others have commercial quantum key distribution solutions for encrypting secure communications, and several are selling QRNG chips (quantum random number generation) for generating truly random codes.
The Samsung Galaxy Quantum 2 phone actually has a QRNG chip on board that measures 2.5mm square, the world’s smallest random-number generating chip. And at the end of April 2021, The High-BIAS2 project from ColdQuanta announced recent advances and planned testing for their cold atom-based quantum positioning system (QPS), which enables vehicle navigation without a GPS (global positioning system) or GNSS (global navigation satellite system). ColdQuanta expects the breakthrough to benefit “a wide range of billion dollar industries including aerospace, autonomous vehicles, marine transportation, oil and gas excavation and more.”
Multiple areas of quantum research now include computing, sensors, online cryptographic security, quantum encryption, communications, and quantum networks, including a future quantum internet—all applying the new rules of quantum physics. The road on which Google has embarked in Santa Barbara becomes more crowded each day.