Scientists Connect Quantum Bits with Sound over Record Distances

(Phys.org) Scientists with the Institute for Molecular Engineering at the University of Chicago have made two breakthroughs in the quest to develop quantum technology. In one study, they entangled two quantum bits using sound for the first time; in another, they built the highest-quality long-range link between two qubits to date.
“Both of these are transformative steps forward to quantum communications,” said co-author Andrew Cleland, the John A. MacLean Sr. Professor of Molecular Engineering at the IME and UChicago-affiliated Argonne National Laboratory.
Cleland’s lab was able to build a system out of superconducting qubits that exchanged quantum information along a track nearly a meter long with extremely strong fidelity—with far higher performance has been previously demonstrated. “The coupling was so strong that we can demonstrate a quantum phenomenon called ‘quantum ping-pong’—sending and then catching individual photons as they bounce back,” said Youpeng Zhong, a graduate student in Cleland’s group.