Decoherence-free radiofrequency dressed subspaces

TL;DR

This paper demonstrates how to engineer radiofrequency dressing conditions to create decoherence-free subspaces in atomic hyperfine states, significantly reducing magnetic noise effects for quantum applications.

Contribution

It introduces 'magic' dressing conditions and a bi-chromatic scheme to suppress electromagnetic noise, enhancing coherence in atomic hyperfine transitions.

Findings

Identification of 'magic' dressing conditions that suppress decoherence

Development of a bi-chromatic dressing configuration for noise reduction

Protection of multiple hyperfine transitions at low magnetic fields

Abstract

We study the spectral signatures and coherence properties of radiofrequency dressed hyperfine Zeeman sub-levels of 87Rb. Experimentally, we engineer combinations of static and RF magnetic fields to modify the response of the atomic spin states to environmental magnetic field noise. We demonstrate analytically and experimentally the existence of 'magic' dressing conditions where decoherence due to electromagnetic field noise is strongly suppressed. Building upon this result, we propose a bi-chromatic dressing configuration that reduces the global sensitivity of the atomic ground states to low-frequency noise, and enables the simultaneous protection of multiple transitions between the two ground hyperfine manifolds of atomic alkali species. Our methods produce protected transitions between any pair of hyperfine sub-levels at arbitrary (low) DC-magnetic fields.