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. The work brings us closer to harnessing quantum technology to make more powerful computers, ultra-sensitive sensors and secure transmissions.
“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. A leader in the development of superconducting quantum technology, he led the team that built the first “quantum machine,” demonstrating quantum performance in a mechanical resonator. “One of these experiments shows the precision and accuracy we can now achieve, and the other demonstrates a fundamental new ability for these qubits.”
Scientists and engineers see enormous potential in quantum technology, a field that uses the strange properties of the tiniest particles in nature to manipulate and transmit information. For example, under certain conditions, two particles can be “entangled”—their fates linked even when they’re not physically connected. Entangling particles allows you to do all kinds of cool things, like transmit information instantly to space or make unhackable networks.
But the technology has a long way to go—literally: A huge challenge is sending quantum information any substantial amount of distance, along cables or fibers.
In a study published April 22 in Nature Physics, 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 and the first author of the paper.
—Prof. Jacqueline Stewart
