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Z. B. Ni

Publications and source records attributed to Z. B. Ni.

3 recordsLinked to original sources

Multi-Modal Spectroscopy Theory for Ultrafast Control of Rabi Oscillations

We propose a three-cavity scheme to realize full control of the emitter-cavity coupling strength in cavity quantum electrodynamics (cQED). The involvement of coupled oscillators gives rise to transient dynamics comprising multiple spectral components, which significantly increases the numerical cost to resolve the fluorescence spectrum in the time domain. A generalized sensor method is hence developed to simplify the calculation process for the characterization of nonstationary quantum dynamics. Multi-modal spectroscopy reveals the emergence, splitting, and disappearance of supermodes in real time. Based on the depletion of the zero-energy supermode, ultrafast switching of Rabi oscillations is demonstrated for time-domain multi-modal spectroscopy. These results exhibit a consistent picture from the spectral control of multiple oscillators to the quantum observation in ultrafast dynamics, which establishes the sensor method as a powerful theoretical tool for the ultrafast spectroscopy of cQED systems.

quant-ph

Phase-preserving control of Floquet-engineered cavity quantum electrodynamics

We propose a Floquet-engineered framework for the coherent control of the light-matter interaction in a two-level system (TLS) located in a time-modulated cavity. Strictly phase-preserving operation of the TLS-cavity interaction is demonstrated, allowing the interrupt and retrieval of coherent Rabi oscillations without the loss of quantum information. By introducing a phonon reservoir, it is proved that the frequency instability induced from non-Markovian processes does not produce significant phase decoherence during Floquet modulation. Our results provide new insights into the fundamental physics of a driven quantum system and establish Floquet engineering as a powerful tool for coherent quantum information processing.

quant-ph

Enhancing Photon Indistinguishability of Spectrally Mismatched Single Photons by Cavity Floquet Engineering

We theoretically propose a scheme to enhance the photon indistinguishability of spectrally mismatched single photons via Floquet-engineered optical frequency combs (OFCs) in cavity quantum electrodynamic systems. By periodically modulating two distinct single-photon states under a modulation frequency which is exactly equal to the spectral mismatch of two cavity modes, a pair of single-photon frequency-comb (SPFC) states is prepared energy-conservatively based on full unitary operations. The two states show high indistinguishability with an ideal $g^{(2)}_\mathrm{HOM}(0)$ down to zero due to the superposition of intensity-matched single-photon states coherently distributed across the teeth of the combs.

quant-ph