"Doubly-magic" conditions in magic-wavelength trapping of ultracold alkalis

TL;DR

This paper demonstrates that microwave clock transitions in alkali atoms can be made insensitive to both laser intensity and magnetic field fluctuations by using specific trapping wavelengths and magnetic field values, enabling more precise quantum measurements.

Contribution

It introduces the concept of 'doubly-magic' conditions for alkali atoms, allowing robust trapping of hyperfine states against perturbations, which was previously an open challenge.

Findings

Doubly-magic conditions are achievable at specific wavelengths and magnetic fields.

Multiphoton transitions can be used to realize these conditions.

Enhanced precision in spectroscopy and quantum information applications.

Abstract

In experiments with trapped atoms, atomic energy levels are shifted by the trapping optical and magnetic fields. Regardless of this strong perturbation, precision spectroscopy may be still carried out using specially crafted, "magic" trapping fields. Finding these conditions for particularly valuable microwave clock transitions in alkalis has so far remained an open challenge. Here I demonstrate that the microwave clock transitions for alkalis may be indeed made impervious to both trapping laser intensity and fluctuations of magnetic fields. I consider driving multiphoton transitions between the clock levels and show that these "doubly-magic" conditions are realized at special values of trapping laser wavelengths and fixed values of relatively weak magnetic fields. This finding has implications for precision measurements and quantum information processing with qubits stored in hyperfine manifolds.