A team of researchers at the University of Texas at San Antonio (UTSA) has set a world record for innovation in quantum computing. R. Tyler Sutherland, an assistant professor in the College of Sciences Department of Physics and Astronomy and the College of Engineering and Integrated Design’s Department of Electrical Engineering, developed a new theory for the record setting experiment.
Sutherland has research experience in quantum optics, and he earned his Ph.D at Purdue University. He then went on to Lawrence Livermore National Laboratory for his postdoc, and his work included experimental applications for quantum computers.
The World Record
The team set the world record for the most accurate entangling gate ever demonstrated without lasers. An entangling gate creates an operation on the second of two qubits that is conditioned on the state of the first.
The paper detailing the new quantum computing accomplished was published in the scientific journal Nature. It is titled “High-fidelity laser-free universal control of trapped-ion qubits.”
“For example, if the state of qubit A is 0, an entangling gate doesn’t do anything to qubit B, but if the state of qubit A is 1, then the gate flips the state of qubit B from 0 to 1 or 1 to 0,” he said. “The name comes from the fact that this can generate a quantum mechanical property called ‘entanglement’ between the qubits.”
“Laser-Free” Entangling Gates
According to Sutherland, quantum computers become easier to use and more cost-effective when the entangling gates are made “laser-free.” Compared to the tens of thousands of dollars it costs for a laser, the price of an integrated circuit is far less, and it performs the same actions.
“Laser-free gate methods do not have the drawbacks of photon scattering, energy, cost and calibration that are typically associated with using lasers,” said Sutherland. “This alternative gate method matches the accuracy of lasers by instead using microwaves, which are less expensive and easier to calibrate.”
Out of the many revolutionary and promising applications of quantum computers, one of the greatest is their ability to simulate quantum mechanical processes themselves. This could be something like chemical reactions, and it could exponentially reduce the experimental trial and error that is needed to solve certain problems. Quantum computers are able to solve some of computing’s most complex problems, and they can do so far faster than classical supercomputers.
“Broadly speaking, the goal of my research is to increase human control over quantum mechanics,” said Sutherland. “Giving people power over a different part of nature hands them a new toolkit. What they will eventually build with it is uncertain.”