The U.S. Department of Energy’s (DOE) Argonne National Laboratory is making exciting advances in quantum information science (QIS). QIS explores how tiny particles sense and relay information in new ways. The research could lead to a quantum computer that performs previously impossible calculations or an exceptionally secure network for transmitting data.
The recent milestones play out on small scales: across the space of a few seconds or across a single layer of atoms. Though measured in minuscule increments, each advance contributes to new ways to harness quantum mechanics for computing, communication and sensing.
Quantum information research has been mostly about the science until recently. Now, especially over the past decade, there’s been increased interest in turning the science into technology.
Supratik Guha
Argonne is a hub for quantum technology research, pioneering work that dates back to Argonne emeritus scientist Paul Benioff’s groundbreaking theoretical proposal for a quantum computer in the 1980s. Today, research continues through Argonne’s QIS research and its leadership of Q-NEXT, a DOE National Quantum Information Science Research Center. Here are three ways Argonne research has been pushing the frontiers of QIS.
Forging New Materials
In the quantum world, information can be conveyed via a single electron — the part of an atom that carries a negative electric charge — or a particle of light. The ability to store and manipulate such particles requires the development of materials that can be controlled at subatomic levels. Argonne scientists have assembled a material based on copper and carbon monoxide molecules to mimic graphene, a promising but difficult-to-make host for quantum data.
This novel quantum test bed confirmed predictions about the behavior of electrons in graphene.
“It’s incredibly rare for an experimental system to match theoretical predictions so perfectly,” said Dan Trainer, who worked on the project while he was a postdoctoral appointee at Argonne.
To both assemble and study the material, Trainer and colleagues used a scanning tunneling microscope at Argonne’s Center for Nanoscale Materials, a DOE Office of Science user facility.
Researchers also have made important strides with other materials that could be used for quantum applications. A team at Argonne and the University of Chicago created a record-breaking qubit — the quantum version of a computer bit — from the accessible and inexpensive compound silicon carbide. Qubits can be difficult to read efficiently, and their signals are notoriously fleeting, lasting on the order of milliseconds. The qubit was able to be read on demand, and its quantum state stayed intact for over five seconds.
In another study, Argonne researchers demonstrated the use of pure diamond membranes as platforms for storing and processing quantum information. DOE’s Small Business Innovation Research (SBIR) and Small Business Technology Transfer (STTR) awards are funding further research on a method to commercially produce this quantum diamond material. The diamond concept is part of broader research aimed at exploiting defects in crystals for quantum systems. Diamond membranes belong to a group of materials, solid-state spin qubits, that was featured on the cover of a special issue of the journal Nature Reviews Materials.
Running Powerful Simulations
Quantum computers and related technologies rely on a fundamental understanding of how atoms and their constituents behave, and how they might be tuned to represent data in a quantum system. Computer simulations can reveal the dynamics of quantum objects in ways no experiment could match. In one study, researchers showed how missing atoms known as vacancies in crystalline materials could be transformed into quantum information.
“By performing computer simulations at the atomic scale with high-performance computers, we can watch defects forming, moving, disappearing and rotating in a sample over time at different temperatures,” said Elizabeth Lee, a postdoctoral researcher in the UChicago Pritzker School of Molecular Engineering who worked on the project. “This is something that cannot be done experimentally, at present.”
In another study, Argonne researchers used quantum computers to simulate quantum materials. The study tackled the problem of “noisy” calculations on quantum computers, a problem where interference from the hardware causes the computer to return slightly different results for the same operation. By simulating different states of qubits in a quantum computing system, the researchers arrived at a proposed method for improving its accuracy on calculations.
Both of these studies drew, in part, on resources provided by the Argonne Leadership Computing Facility, a DOE Office of Science user facility.
Leadership in the Quantum Science Community
Argonne convenes some of the world’s foremost experts in QIS. By partnering on activities as varied as workshops, movie screenings and undergraduate fellowships, the lab is fostering crucial conversations and collaborations in this burgeoning field.
Partnerships are key: Q-NEXT has drawn more than 20 from industry and academia, most recently Amazon Web Services, the Massachusetts Institute of Technology and JPMorgan Chase.
A recent report from Q-NEXT, “A Roadmap for Quantum Interconnects,” laid out the necessary work ahead to develop the technologies for distributing quantum information between systems and across distances to enable quantum computing, communications and sensing.
“Quantum information research has been mostly about the science until recently,” said Supratik Guha, Q-NEXT chief technology officer, discussing the roadmap. “Now, especially over the past decade, there’s been increased interest in turning the science into technology.”
Argonne will soon officially open the Argonne Quantum Foundry, a national resource for creating and delivering high-quality materials for quantum devices. It is one of two national foundries that will support Q-NEXT research. The opening of a second foundry at DOE’s SLAC National Accelerator Laboratory is imminent.
“The foundries will have a positive impact not just for research, but also for the quantum ecosystem, providing a robust supply chain of materials from which industry and other U.S. stakeholders will benefit,” said Q-NEXT Director David Awschalom, who is also an Argonne senior scientist, the Liew Family Professor of Molecular Engineering and vice dean for research and infrastructure at the University of Chicago Pritzker School of Molecular Engineering, and the director of the Chicago Quantum Exchange. “We expect that, as a unique facility in the Midwest, the Argonne Quantum Foundry will accelerate progress in quantum information science both for the region and the nation.”