4/24/2026 Siv Schwink for Illinois Physics
Pfaff will take a new approach to quantum memories based on some of the longest-lived quantum systems known, to address the problem of decoherence.
Written by Siv Schwink for Illinois Physics
Illinois Physics Professor Wolfgang Pfaff has been selected for a 2026 National Science Foundation (NSF) Faculty Early Career Development (CAREER) Award. This prestigious award recognizes outstanding junior faculty who excel in both research and teaching and who demonstrate the capacity to become lifetime leaders in their respective fields.
Pfaff, who is a member of the Illinois Quantum Information Science and Technology Center and the Chicago Quantum Exchange, is focused on developing scalable, modular quantum systems based on superconducting and hybrid circuits. His winning CAREER Award project entitled “Encoding ultra-coherent logical qubits in spin ensembles” will tackle one of the central obstacles standing between today's quantum computers and the transformative machines that researchers envision for the future. If successful, Pfaff’s research could extend the useful lifetime of quantum information by orders of magnitude and mark a major step toward practical, large-scale quantum computers.
Quantum computers have the potential to solve problems that are far out of reach for even the largest conventional supercomputers—from designing new medicines and materials to cracking long-standing puzzles in physics and chemistry. But quantum information is notoriously fragile: the quantum states that carry it tend to fade away in a fraction of a second, limiting how much useful computation can happen before errors take over.
Superconducting circuits are one of the most promising technologies for building quantum computers because they offer fast and precise control. However, they lose their quantum information quickly because of tiny imperfections in the superconducting materials.
Pfaff's project takes a hybrid approach to addressing decoherence.
Pfaff explained, “This new research will pair superconducting circuits with ensembles of atomic spins embedded in specially chosen crystals—natural quantum systems that can retain information for seconds, minutes, or, in some cases, even hours. By developing new kinds of electronic couplers that can rapidly shuttle quantum information back and forth between a superconducting chip and a crystal, my team aims to build a quantum memory that combines the best of both worlds: the speed and controllability of a superconducting circuit with the long-lasting stability of a spin system.”
A second thrust of the project pushes this idea even further by developing couplers that can operate within strong magnetic fields.
“Many of the most promising spin systems only reach peak performance when a magnetic field is applied—but the standard building blocks of superconducting circuits stop working properly in such an environment,” Pfaff continued. “My group will design a new generation of couplers made from ultra-thin superconducting films that remain functional in magnetic fields, opening the door to quantum memories based on some of the longest-lived quantum systems known.”
Pfaff received his Ph.D. in applied physics from Delft University of Technology (Netherlands) in 2013, where he worked under the supervision of Ronald Hanson. Pfaff then held a postdoctoral appointment at Yale University from 2014 to 2017, working in the lab of Rob Schoelkopf on highly coherent superconducting cavities as quantum memories and pioneering protocols for distributing quantum information between superconducting devices.
After his postdoctoral appointment, Pfaff joined Microsoft Quantum Lab Delft in 2017, where he applied his expertise in superconducting quantum devices to investigate how future topologically protected qubits can be measured and controlled. In 2020, Pfaff joined the faculty of the Department of Physics at Illinois Grainger Engineering.