Northwestern is key partner in $115 million national center to build revolutionary quantum computer

The initiative provides the new Superconducting Quantum Materials and Systems Center (SQMS) with a planned $115 million from the DOE over five years with the goal of building and deploying a beyond-state-of-the-art quantum computer based on superconducting technologies. The research will focus on breakthroughs important for medicine, life sciences, national security and physics. The center also will develop new quantum sensors that could lead to the discovery of the nature of dark matter and other elusive subatomic particles.

Anna Grassellino of Fermilab, who also has a joint appointment at Northwestern as a faculty member in the department of physics and astronomy, will be the center’s director. James Sauls, professor of physics at Northwestern, will be the center’s deputy director.

“We are thankful and honored to have this unique opportunity to be a national center for advancing quantum science and technology,” Grassellino said. “We have a focused mission: build something revolutionary. This center brings together the right expertise and motivation to accomplish that mission.” 

Seventeen Northwestern faculty members with deep expertise in quantum science are affiliated with the center. They have interdisciplinary knowledge in areas vital for advancing quantum science, including atomic and optical physics, materials science, data science, superconducting technologies and theoretical physics.

“The breadth of the SQMS physics, materials science, device fabrication and characterization technology combined with our expertise in large-scale integration capabilities is unprecedented for superconducting quantum science and technology,” said Sauls, who serves on the executive committee of the University’s quantum information research and engineering initiative (INQUIRE). “As part of the network of National Quantum Initiative centers, SQMS will contribute to U.S. leadership in quantum science for years to come.”

The Northwestern faculty come from the department of physics and astronomy in the Weinberg College of Arts and Sciences and the departments of materials science and engineering and of electrical and computer engineering at the McCormick School of Engineering.

Interdisciplinary expertise is tapped

The materials science and physics faculty, combined with the University’s cryogenic and materials characterization facilities, will play a central role in the basic science research to improve the performance of superconducting qubits and microwave cavities for quantum computing and sensing applications. 

Likewise, Northwestern expertise in superconducting materials theory and device development is instrumental in the development of quantum devices for sensing and quantum processors for computing. Northwestern also will be the hub of quantum workforce development for the SQMS Center, training students and postdoctoral researchers.

The SQMS Center is part of $625 million federal program to facilitate and foster quantum innovation in the United States. The 2018 National Quantum Initiative Act called for a long-term, large-scale commitment of U.S. scientific and technological resources to quantum science. Total planned DOE funding for the center is $115 million over five years, with $15 million in fiscal year 2020 dollars and out year funding contingent on congressional appropriations. SQMS funding also includes an additional $8 million in matching contributions from center partners.

In addition to the 17 researchers involved in the SQMS Center, Northwestern also has three faculty members affiliated with one of the other newly funded National Quantum Initiative centers — Q-NEXT at Argonne National Laboratory — while Jens Koch, co-inventor of the transmon qubit and member of SQMS, is also part of C2QA at Brookhaven National Laboratory. 

Related: See list at bottom of affiliated Northwestern faculty.

The revolutionary leaps in quantum computing and sensing that SQMS aims for will be enabled by a unique multidisciplinary collaboration that includes 20 partners — national laboratories, academic institutions and industry. The collaboration brings together world leaders in all key aspects: from identifying qubits’ quality limitations at the nanometer scale to fabrication and scale-up capabilities into multiqubit quantum computers to the exploration of new applications from fundamental physics to national security. 

Sauls anticipates “great opportunities for synergy” between SQMS and Brookhaven’s C2QA center, affiliated with Princeton and Yale universities, based on existing and previous research collaborations and the shared focus on superconducting-based quantum processors. 

Addressing the quantum coherence challenge

At the heart of SQMS research will be solving one of the most pressing problems in quantum information science: the length of time that a qubit, the basic element of a quantum computer, can retain information, also called quantum coherence. Understanding and mitigating sources of decoherence that limit performance of quantum devices is critical to engineering in next-generation quantum computers and sensors.

“Unless we address and overcome the issue of quantum system decoherence, we will not be able to build quantum computers that solve new complex and important problems,” Grassellino said. “The same applies to quantum sensors with the range of sensitivity needed to address long-standing questions in many fields of science. Overcoming this crucial limitation would allow us to have a great impact in the life sciences, biology, medicine and national security and enable measurements of incomparable precision and sensitivity in basic science.”  

The SQMS Center’s ambitious goals in computing and sensing are driven in part by Fermilab's achievement of world-leading coherence times in components called superconducting cavities, which were developed for particle accelerators used in Fermilab’s particle physics experiments. Researchers have expanded the use of Fermilab cavities into the quantum regime.  

“We have the most coherent — by a factor of more than 200 — 3-D superconducting cavities in the world, which will be turned into quantum processors with unprecedented performance by combining them with Rigetti Computing’s state-of-the-art planar structures,” said Alexander Romanenko, a Fermilab scientist, Northwestern faculty member and SQMS technology thrust leader. “This long coherence would not only enable qubits to be long-lived, but it would also allow them to be all connected to each other, opening qualitatively new opportunities for applications.” 

To advance quantum coherence even further, SQMS collaborators will launch a materials-science investigation of unprecedented scale to gain insights into the fundamental limiting mechanisms of cavities and qubits, working to understand the quantum properties of superconducting device operation at the nanoscale and in the microwave regime. Northwestern’s expertise in low temperature physics will play a key role in developing a cryogenic testbed for measuring and characterizing superconducting quantum devices for qubits and sensors.

National and international collaborators

“Now is the time to harness the strengths of the DOE laboratories and partners to identify the underlying mechanisms limiting quantum devices in order to push their performance to the next level for quantum computing and sensing applications,” said SQMS Chief Engineer Matt Kramerof Ames Laboratory.

Northwestern, Ames Laboratory, Fermilab, Rigetti Computing, the National Institute of Standards and Technology, the Italian National Institute for Nuclear Physics and several universities are partnering within the center to contribute world-class materials science and superconductivity expertise to target sources of decoherence. 

Northwestern and Fermilab have previously collaborated, including in the creation of a joint research center focused on basic science, applied physics and superconducting technologies called the Center for Applied Physics and Superconducting Technologies (CAPST), co-directed by Sauls and Grassellino. A key area of investigation for CAPST researchers has been developing a fundamental understanding of the physics associated with superconducting radio-frequency (SRF) cavities for particle acceleration. These same SRF cavities now open new opportunities in quantum device and computing technologies. The SQMS Center award will amount to an $18 million award to Northwestern through CAPST. 

In addition to Northwestern and Fermilab, the Superconducting Quantum Materials and Systems Center institutions include DOE’s Ames Laboratory, Colorado School of Mines, Goldman Sachs, Illinois Institute of Technology, the Italian National Institute for Nuclear Physics, Janis Research, Johns Hopkins University, Lockheed Martin, NASA Ames Research Center, National Institute of Standards and Technology, Rigetti Computing, Stanford University, Temple University, Unitary Fund, University of Arizona, University of Colorado Boulder, University of Illinois at Urbana Champaign and University of Padova, Italy.

Rigetti Computing will provide crucial state-of-the-art qubit fabrication and full stack quantum computing capabilities required for building the SQMS quantum computer. The NASA Ames Research Center quantum group, led by SQMS Chief Scientist Eleanor Rieffel, will bring strengths in quantum algorithms, programming and simulation that will be crucial to use the quantum processors developed by the SQMS Center. The Italian Institute for Nuclear Physics, contributes expertise in detector development, cryogenics and environmental measurements, including the Gran Sasso national laboratories, the world’s largest underground facility devoted to fundamental physics.

“Fermilab is excited to host this national quantum center and work with this extraordinary network of collaborators,” Fermilab Director Nigel Lockyer said. “This initiative aligns with Fermilab and its mission. It will help us answer important particle physics questions, and, at the same time, we will contribute to advancements in quantum information science with our strengths in particle accelerator technologies, such as superconducting radio-frequency devices and cryogenics.”