Today at Berkeley Lab

Workshop Focuses on Quantum Information Science

On Wednesday, Oct. 25, about 75 Berkeley Lab and UC Berkeley scientists gathered in the Building 66 auditorium for a daylong workshop focused on enhancing connections across the Berkeley community related to quantum information science (QIS).

The promise of QIS was a common thread throughout the workshop’s more than two dozen talks. Quantum computing could help solve some of science’s hardest problems in chemistry, materials, and other disciplines. And advances in detectors that capitalize on quantum phenomena could lead to new discoveries in precision measurements of fundamental constants as well as high-energy physics. Developing these and other QIS-related technologies will require overcoming significant research challenges – and Berkeley Lab’s scientists and facilities are well positioned to play a significant role in these efforts.

“There is tremendous interest across the Lab in quantum information science,” said Berkeley Lab Deputy Director Horst Simon in opening remarks. “With this workshop, we want to bring together everyone here engaged in this research, from computing to sensing to metrology to materials. The goal is a Lab-wide effort that is greater than the sum of each of us individually.”

As part of the workshop kickoff, Barbara Helland, associate director of the Advanced Scientific Computing Research (ASCR) program in DOE’s Office of Science, offered the perspective from the Office of Science via phone. She explained that QIS will be a cross-cutting initiative spanning the Office of Science.

In addition, Berkeley Lab scientists continue to help shape this initiative, and will participate in two DOE Basic Energy Sciences-convened round tables this week that will identify opportunities for basic research for quantum materials for QIS, and quantum computing for quantum materials.

Toward Quantum Computing and Simulation

The lead-off topic was quantum computing, an emerging field that seeks to build new computing architectures that take explicit advantage of quantum mechanics. By storing information in quantum bits, or qubits, quantum computers hold the promise of tackling complex challenges too intractable for today’s classic computers, as well as completing calculations in a fraction of the time.

Jonathan Carter, deputy director of the Lab’s Computing Sciences Area, outlined several challenges that need to be addressed. These include higher fidelity qubits, scalability of the technology, networking quantum devices together, quantum memories, and algorithm development.

Thanks to Laboratory Directed Research and Development (LDRD)-funded projects, and DOE funding announced in September, Berkeley Lab has significant momentum in quantum computing research. Specifically, Lab scientists will lead a DOE Quantum Algorithms Team and will lead one of DOE’s Quantum Pathfinder testbeds – the Advanced Quantum-Enabled Simulation (AQuES) Testbed. In addition to the Computing Sciences Area, these projects will tap the expertise of researchers in the Lab’s Accelerator Technology and Applied Physics, Materials Sciences, and Engineering divisions, as well as the capabilities of the Molecular Foundry and National Energy Research Scientific Computing Center (NERSC).

The Many Sides of Quantum Materials

Workshop participants also highlighted the close relationship between research in quantum materials and quantum computing. Joel Moore, a faculty scientist in the Materials Sciences Division and a UC Berkeley professor of physics, posed the possibility that materials science may be the “killer app” for quantum information science.

Quantum computers may one day predict the properties needed for high-temperature superconductivity. At the same time, studies of defects and interface properties in materials may help researchers understand the factors that contribute to qubit decoherence.

Several speakers highlighted the benefits of having DOE Office of Science User Facilities on site. Work at the Molecular Foundry is already being used to study quantum behavior and atomic structures of 2-D materials, and Molecular Foundry nanofabrication facilities are also contributing. Once the planned upgrade for the Advanced Light Source is complete, the synchrotron will be the brightest light source in the soft X-ray range, making it indispensable in the study of the electronic and chemical properties of materials.

The Quest for Better Quantum Measurements

Irfan Siddiqi, faculty scientist in the Materials Sciences Division and a UC Berkeley physics professor, led a session on research in quantum metrology, which he described as the process for measuring information at or beyond the quantum limit for precision.

He described how the precision and efficiency of quantum detectors can be improved by using parametric amplifiers and a technique known as “squeezing,” enabling for example the observation of individual trajectories of one or more qubits. Siddiqi is also founding director of the Center for Quantum Coherent Science at UC Berkeley.

Other speakers described how new generations of quantum metrology tools could lead to higher-resolution medical imaging and electron microscopy, improve X-ray studies of quantum materials and devices at the ALS, and provide new precision in measurements of the known forces of physics, among other examples.

A Renewed Sense of Urgency for Quantum Sensing

Maurice Garcia-Sciveres, a senior scientist in the Physics Division whose research specializes in pixel detectors, noted that there is a growing need in the field of high-energy physics and other fields for quantum sensing devices, such as sensors that can detect individual energy quanta with no background.

Among the talks, Karl van Bibber, professor and chairman of the UC Berkeley Department of Nuclear Engineering who has participated in the hunt for dark matter particles known as axions, noted, “Quantum devices in particle astrophysics have been part of the fabric of what has allowed our field to go ahead for a long time.”

And Kathryn Zurek, a senior scientist in the Physics Division and a theorist whose work focuses on the boundary of particle physics with cosmology, suggested that while detectors searching for dark matter particles have so far used a “billiard-ball” approach – searching for signals from new particles that “bump into” atomic nuclei – there is a pressing need for new detectors that can detect lower mass particles that are too feeble to be seen in this way.

Next Steps

Berkeley Lab’s QIS steering group will take input from the workshop and work toward a Lab-wide strategy. For more information about the QIS steering group, contact Peter Denes.