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Updated: Mar 29, 2026

Gradient Echo Quantum Memory in Warm Atomic Vapor
Published on: November 11, 2013
Reversibility of dynamics and multiple-quantum coherences
1Department of Chemistry, Kent State University, Kent, Ohio 44242, USA.
Abstract:
In spin systems, the decay of the Loschmidt echo in the time-reversal experiment (evolution-perturbation-time-reversed evolution) is linked to the generation of multiple-quantum (MQ) coherences. Unlimited growth of the MQ coherences leads to irreversibility of dynamics. In some cases, one can expect that the deviation of the Loschmidt echo and the second moment of the MQ intensities distribution are linear in time. The criteria of such behavior, called weak irreversibility, are formulated. The proposed approach can be extended beyond spin systems, in order to analyze some general aspects of reversibility of many-body quantum dynamics.
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