Asymmetric Floquet sidebands with long-lived symmetric coherence under spin-1 Bose-Einstein-condensate continuous dynamical decoupling
Phys. Rev. A 114, 023307 – Published 5 August, 2026
DOI: https://doi.org/10.1103/rbfn-72vl
Abstract
Continuous dynamical decoupling is an effective technique for extending quantum coherence by applying a continuous driving field that strongly suppresses the sensitivity of quantum states to magnetic-field fluctuations in the dressed-state basis. We experimentally measure the dressed-state spectrum of a spin-1 Bose-Einstein condensate under continuous rf driving and investigate the properties of the resulting sidebands from a Floquet-theory perspective. It is found that under resonant rf driving, two of the three dressed states exhibit markedly enhanced coherence times, and both the coherence time and the coherence coupling strength are symmetric for the two conjugate Floquet sidebands. In contrast, under off-resonant rf driving, although the coherence times are symmetrically reduced for the two conjugate Floquet sidebands, the coherence coupling strength exhibits a completely asymmetric behavior. Our study demonstrates the feasibility of implementing continuous dynamical decoupling for coherent quantum control in ultracold atomic systems and provides both experimental and theoretical foundations for dressed-state-based quantum control and precision measurement.
