Millisecond-Lived Circular Rydberg Atoms in a Room-Temperature Experiment.

Circular Rydberg states are excellent tools for quantum technologies, with large mutual interactions and long lifetimes in the tens of milliseconds range, 2 orders of magnitude larger than those of laser-accessible Rydberg states. However, such lifetimes are observed only at zero temperature. At room temperature, blackbody-radiation-induced transfers cancel this essential asset of circular states, which have thus been used mostly so far in specific, complex cryogenic experiments. We demonstrate here, on a laser-cooled atomic sample, a circular state lifetime of more than 1 millisecond at room temperature for a principal quantum number 60. A simple plane-parallel capacitor efficiently inhibits the blackbody-radiation-induced transfers. One of the capacitor electrodes is fully transparent and provides large optical access to the atoms. This result paves the way to a wide range of quantum metrology and quantum simulation room-temperature experiments with long-lived, trapped circular Rydberg atoms in inhibition capacitors with full optical access.