Control of conditional quantum beats in cavity QED: amplitude decoherence and phase shifts

Abstract

We implement a simple feedback mechanism on a two-mode cavity QED system to preserve the Zeeman coherence of a ground state superposition that generates quantum beats on the second-order correlation function. Our investigation includes theoretical and experimental studies that show how to prevent a shift away from the Larmor frequency and associated decoherence caused by Rayleigh scattering. The protocol consists of turning off the drive of the system after the detection of a first photon and letting it evolve in the dark. Turning the drive back on after a pre-set time reveals a phase accumulated only from Larmor precession, with the amplitude of the quantum beat more than a factor of two larger than with continuous drive.

arXiv comment17 pages, 9 figures

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Cited by in corpus (7)

• Environment assisted speed-up of the field evolution in cavity QED
• Optimal control of a qubit in an optical cavity
• High-Speed Driving of a Two-Level System
• Time-dependent spectra of quantum beats
• Quantum interference in the resonance fluorescence of a $J=1/2$-$J^{\prime }=1/2$ atomic system: Quantum beats, nonclassicality, and non-Gaussianity
• Nanosecond-timescale development of Faraday rotation in an ultracold gas
• Feedback in a cavity QED system for control of quantum beats