STORRS, CT — UConn physicists are entering the global race to fix a microscopic flaw that has long stifled quantum computing.
Through a $5.48 million grant from the Air Force Office of Scientific Research (AFOSR), UConn joins Rigetti Computing and a team of international partners to investigate and eliminate two-level system (TLS) defects in superconducting qubits.
The defects destabilize the delicate quantum states that qubits rely on to process information.
“UConn is positioning itself as a key hub for quantum materials and quantum technologies research. The goal isn’t just to keep pace – it’s to lead,” said Prof. Alexander Balatsky, a condensed matter theorist at the Institute for Materials Science.
Balatsky’s team will use supercomputers to simulate how TLS defects form and behave at the atomic scale.
The focus is on improving Josephson tunnel junctions—oxide-based barriers crucial to quantum chip design.
“Just as it’s difficult to hold a conversation in a crowded room due to background conversations, TLSs create a kind of noise that drowns out quantum behavior,” Balatsky said.
TLSs were once thought to be permanent, but that assumption was overturned by Rigetti’s 2024 study introducing a method called Alternating-Bias Assisting Annealing (ABAA).
The technique uses room-temperature electric pulses to reduce TLS disruption in quantum chips.
“Rigetti is excited to work with experts at University of Connecticut to understand the fundamental materials science and physics of Josephson tunnel junctions,” said Rigetti’s senior principal scientist David Pappas.
“This project gives us access to the resources and expertise to unlock the full potential of ABAA and gain a foundational understanding of defects in superconducting qubits,” said Rigetti CEO Subodh Kulkarni.
The consortium includes Iowa State University, Royal Melbourne Institute of Technology, and Lawrence Livermore National Laboratory. UConn’s participation supports its role in QuantumCT, a statewide initiative with Yale and other partners aimed at making Connecticut a national leader in quantum technology.
“The future potential of quantum hinges on engineering ultra-stable materials which can withstand the devastating effects of TLSs,” Balatsky said. “We don’t yet know which materials will dominate quantum tech. But materials research is the foundation—without it, the entire stack collapses.”
