New Research on Quantum Computing Stems from UCSB Professors

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Illustration by Lauren Luna

Xander Apicella
Science and Tech Editor

A quantum revolution is coming, and UC Santa Barbara (UCSB) is leading the charge. In a talk at the Good Space in Goleta — last Thursday, Feb. 27 — three UCSB professors, the presentation’s expert panelists, made that clear. These grandiose titles and achievements speak to the degree to which the field of quantum computing, and quantum physics in general, have benefited from the research and innovations of UCSB professors over the last decade. 

Dr. Zhenghan Wang is a UCSB professor on permanent leave building Microsoft’s first quantum computer as a researcher at the company’s Station Q. Dr. Ania Jayich is an active UCSB professor and a co-director of the world’s first ever Quantum Foundry, an institute funded by the National Science Foundation (NSF) and being built at UCSB. Dr. John M. Martinis leads a lab group that was hired by Google to develop their first quantum computer. He is now lead research scientist at Google’s Quantum AI Initiative — the leader of the team responsible for the company’s Quantum Supremacy announcement at the end of last year.

Classical computing — performed by devices like your laptop, phone, and micro-controllers in various products from cars to digital clocks used in daily life — operate by sending and receiving information in the form of bits, which can then be decided to perform the desired operation. Bits have two states, they can either be a zero or a one.

Quantum computing uses entangled quantum bits, or qubits, to perform its operations. These qubits need not be only zero or one, they are probabilistic rather than defined. They are neither zero nor one, but somewhere in between. This concept is difficult to wrap one’s head around, but it can reap major benefits in certain algorithms and functions classical computers already use today. The major difference is, these operations can, in certain cases, be tried much faster. 

For certain searching algorithms, for example, a classical computer can only test one possibility at a time, because it represents a well-defined, single item in the search. The probabilistic, not-here-nor-there nature of qubits gives a quantum computer the ability to actually test multiple possibilities at once in a search, and in situations complex enough this drastically cuts down on the search’s runtime.

This is, in essence, what quantum supremacy is — what Martinis and his team demonstrated at Google. It is not the overall superiority of quantum computing, but the ability of quantum computing to far surpass classical computing in some cases. In the team’s paper, published in the Nature journal on Oct. 23, 2019, they demonstrated this with their Sycamore processors by using it to “sample one instance of a quantum circuit a million times.” This operation took their computer, which generated quantum states on 53 qubits, approximately 200 seconds. According to their estimates, it would take a cutting-edge supercomputer around 10,000 years to perform the same task.

This increased efficiency, Martinis said, will begin to show its value in optimizing all our industries as the technology advances, talking about optimizations to products like cars, batteries, and even medicine.

Wang’s team at Microsoft’s Station Q is taking a different approach toward quantum computing, creating a topological qubit, which they believe will yield more stable and scalable quantum computers. 

Furthermore, they have developed useful technologies at Microsoft just by understanding how a quantum computer works. Their insights have improved magnetic resonance imaging (MRI) — allowing them to either image in 30 percent of the original time, or get 30 percent better resolution than pre-existing technologies. 

Jayich also mentioned MRI in relation to her work — she has an interest in the broader applications of quantum: applying its concepts to not just computing but other fields, as well. Her work in quantum sensing could allow a quantum MRI device to pick up magnetic fields from individual proteins, whereas the current technology requires around one quintillion conductors to get a meaningful image. 

This focus on the broader scope of quantum makes perfect sense for her work. As co-director of the newfound Quantum Foundry at UCSB, she will be driving toward the institution’s mission — the creation of materials for various quantum fields including sensing, computing, and communication. She will also be at the forefront of a push to create a “new quantum workforce,” a push that will begin at UCSB. She even mentioned the strong possibility of a quantum emphasis or major at the university in the near future. 

Jayich and the other panelists have shown how far UCSB’s experts have pushed the fields of quantum physics. The rapid creation of new jobs and research positions surrounding Goleta and Santa Barbara shows that UCSB will be an integral part of the radical change that quantum is bringing to the world.

Xander Apicella
Xander Apicella is a third-year physics major interested in communicating science of all sorts to anyone and everyone. He flew in from Clarendon, New York, and misses the snow sometimes. He enjoys rock-climbing, reading, writing, and learning something new.

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