Phase-dependent fluctuations of intermittent resonance fluorescence

Abstract

Electron shelving gives rise to bright and dark periods in the resonance fluorescence of a threelevel atom. The corresponding incoherent spectrum contains a very narrow inelastic peak on top of a two-level-like spectrum. Using the theories of balanced and conditional homodyne detection we study ensemble averaged phase-dependent fluctuations of intermittent resonance fluorescence. The sharp peak is found only in the spectra of the squeezed quadrature. In balanced homodyne detection that peak is positive, which greatly reduces the squeezing, also seen in its variance. In conditional homodyne detectionCHD, for weak to moderate laser intensity, the peak is negative, enhancing the squeezing, and for strong fields the sidebands become dispersive which, together with the positive sharp peak dominate the spectrum. The latter effect is due to non-negligible third order fluctuations produced by the atom-laser nonlinearity and the increased steady state population of the shelving state. A simple mathematical approach allows us to obtain accurate analytical results.

Spectral signatures of non-thermal baths in quantum thermalization

“…Actually, in the linear response limit the drive term can be neglected from the coherent dynamics [63], which is really useful for the numerical calculation of the transmission spectrum. On the other hand, if our scheme is implemented in a cavity-QED setup, the fluorescence spectrum of the quantum probe could be measured using, for example, the standard balance homodyne detection schemes [50]. In this technique the phase of the unknown signal is measured by mixing it with a strong local oscillator (LO) in a beam splitter, where the LO is a field with a well-define amplitude and phase.…”

Probing intensity-field correlations of single-molecule surface-enhanced Raman-scattered light

“…This issue has been highlighted both theoretically [23,26] and experimentally [24] in the context of cavity QED systems and subsequently, also theoretically, in resonance fluorescence of a three level atom [37]. Still more recently, Castro-Beltrán et al [38][39][40][41] undertook a thorough analytical treatment of non-Gaussian fluctuations encountered in resonance fluorescence of two-and three-level atomic systems via intensity-field correlation measurements. Further context-dependent studies on the subject have also been reported, such as the light emitted from a two-level atom in an optical cavity [42,43], superconducting artificial atoms [44], fluorescence from optical transitions in Ξ-and V-type three-level atoms [45,46], and the experimental realization of the resonance fluorescence of a single trapped 138 Ba + ion [47].…”

Time-dependent spectra of a three-level atom in the presence of electron shelving

“…In general, the Bloch equations are solved numerically. However, accurate approximate analytical solutions in the resonant case, ∆ = 0, in the regime (9) were obtained by two of us in [7]. The populations and coherences show the typical short-term decay at the rate 3γ + /4 reminiscent of the 2LA dynamics and a long-term decay, at roughly γ a , that signals shelving in the metastable state |a [4].…”

“…Because of the pure spontaneous emission decay, the incoherent nature of the |e − |a − |g channel decouples the equations for the coherences involving the |a state from those of the laser driven |e − |g transition [7,12]. The Bloch equations of the effective two-level system can then be written in compact form as…”

“…An analytic formula for the full stationary spectrum on resonance in the regime (9) has been given in [7]. Time-Dependent Spectrum.-We calculate timedependent spectra (TDS) using the physical spectrum of Eberly and Wódkiewicz [14] S(D, t, Γ) = Γ t t0…”