12/10/2024 Kari Schwink for Illinois Physics
Illinois Physics Professor Wolfgang Pfaff and colleagues at U Chicago and CalTech will investigate entangled quantum states in intentionally noisy 2-qubit and multi-qubit regimes.
Written by Kari Schwink for Illinois Physics
Photo by L. Brian Stauffer, University of Illinois Urbana-Champaign
Illinois Physics Professor Wolfgang Pfaff and colleagues have been awarded an Air Force Office of Scientific Research grant for their quantum computing research proposal entitled “Dissipative synthesis and distillation of remote entanglement.” Pfaff, who is PI on the $2.5 million grant, will collaborate with scientists at the University of Chicago and the California Institute of Technology to investigate qubits that are entangled in their ground state, with applications in quantum computing.
Pfaff explains, “We are trying to observe entanglement, the essential non-classical feature of quantum mechanics, in a setting that is most hostile to it, wherein individual superconducting qubits have no chance of coherently interacting with each other. We want to push this to the extreme where the ground state of these disconnected qubits is actually an entangled state.”
If successful, this research could provide one pathway past a key obstacle to developing functional qubit networks for quantum computing. Qubits are notoriously sensitive to noise—even a few excess photons can remove them from their quantum state, throwing off the entire system.
Up to this point, efforts to address this challenge have prioritized choosing the least interference-sensitive qubit candidates and protecting qubits from environmental noise. Pfaff and his team plan to take the opposite approach.
“We hope that this will teach us something about the limits at which we are able to preserve essential quantum mechanical features in noisy, open quantum systems,” Pfaff says. “If we can get this to work, it might be a very interesting route for stabilizing entanglement in networks of qubits that can be completely separated from each other. And that capability could be very useful in quantum computers or quantum networks.”
At the onset of this project, the experimental setup will be limited to a two-qubit regime. In a later phase, the researchers plan to investigate how multi-qubit entanglement can be stabilized for quantum computing.