Observation of sub-Fourier resonances in a quantum chaotic system

M. S. Santhanam

Pascal Szriftgiser, Jean Ringot, Dominique Delande +1 more

We experimentally show that the response of a quantum-chaotic system can display resonance lines sharper than the inverse of the excitation duration. This allows us to discriminate two neighboring frequencies with a resolution nearly 40 times better than the limit set by the Fourier inequality. Furthermore, numerical studies indicate that there is no limit, but the loss of signal, to this resolution, opening ways for the development of sub-Fourier quantum-chaotic signal processing.

Sarben Sarkar, J.S. Satchell

S Mossmann, C Schumann, H. J Korsch

Quantum decay in an ac driven biased periodic potential modeling cold atoms in optical lattices is studied for a symmetry broken driving. For the case of fully chaotic classical dynamics the classical exponential decay is quantum mechanically suppressed for a driving frequency ωin resonance with the Bloch frequency ω_B, qω=rω_B with integers q and r. Asymptotically an algebraic decay ~t^{-γ} is observed. For r=1 the exponent γagrees with $q$ as predicted by non-Hermitian random matrix theory for q decay channels. The time dependence of the survival probability can be well described by random matrix theory. The frequency dependence of the survival probability shows pronounced resonance peaks with sub-Fourier character.

S Mossmann, Schumann, C, Korsch, H J

Quantum decay in an ac driven biased periodic potential modeling cold atoms in optical lattices is studied for a symmetry broken driving. For the case of fully chaotic classical dynamics the classical exponential decay is quantum mechanically suppressed for a driving frequency omega in resonance with the Bloch frequency omega_B, q omega = r omega_B with integers q and r. Asymptotically an algebraic decay ~ t^{-gamma} is observed. For r=1 the exponent gamma agrees with q as predicted by non-Hermitian random matrix theory for q decay channels. The time dependence of the survival probability can be well described by random matrix theory. The frequency-dependence of the survival probability shows pronounced resonance peaks with sub-Fourier character.

Jian‐Min Yuan, D.H. Feng, George M. Zaslavsky