Researchers at NIST and the University of Maryland have created the first nontrivial “atom circuit” using ultracold gas atoms. The circuit, shaped like a donut, demonstrates a persistent current similar to superconducting electrons in a loop. This marks an important step towards developing an atomic version of a SQUID (Superconducting Quantum Interference Device), which could enable highly sensitive rotation measurements.
The atom circuit includes a tunable barrier that controls the flow of atom current, similar to a weak link in superconducting circuits. The persistent current, sustained for 40 seconds, is a hallmark of superfluidity. This work builds on previous atomic Josephson junction experiments and represents a key advancement in the field of atomtronics, which aims to create ultracold-gas-based precision sensors and devices.
Keywords: atom circuit, superfluidity, Josephson junction, superflow, atomic SQUID