Avoided Crossing and sub-Fourier-sensitivity in Driven Quantum Systems

Description

The response of a linear system to an external perturbation is governed by the Fourier limit, with the inverse of the interaction time constituting a lower limit for the system bandwidth. This does not hold for nonlinear systems, which can thus exhibit sub-Fourier-behavior. The present Letter identifies a mechanism for sub-Fourier-sensitivity in driven quantum systems, which relies on avoided crossing between Floquet states. Features up to three orders of magnitude finer than the Fourier limit are presented.

Abstract

Ministerio de Economía y Competitividad of Spain, Grant No. FIS2016-80244-P

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