Nonclassicality of resonance fluorescence via amplitude-intensity correlations

Phase-dependent fluctuations of resonance fluorescence beyond the squeezing regime

“…The amplitude-intensity correlation is time-symmetric for two-level atom resonance fluorescence [17]. For positive intervals, h ϕ (τ) is the measurement of a quadrature conditioned on a photon detection, the main subject of this paper.…”

“…[9]). A quadrature of the field, E ϕ ∝ σ ϕ , is measured in balance homodyne detection for a time τ whenever a photon is detected, I ∝ σ + σ − , giving a third order correlation in the field amplitude [17], which in normalized form is…”

“…An additional feature of CHD is that it reveals non-Gaussian noise when the amplitude-intensity correlation is asymmetric, i.e., the light's intensity and amplitude have different noise properties, as observed in cavity QED both numerically [9,12] and experimentally [10], and numerically for the resonance fluorescence of a three-level atom [17]. For a two-level atom the small Hilbert space imposes a symmetric correlation [12,17], but the calculations for positive and negative intervals have to be interpreted differently.…”

“…For a two-level atom the small Hilbert space imposes a symmetric correlation [12,17], but the calculations for positive and negative intervals have to be interpreted differently.…”

“…[11][12][13][14][15][16][17]). CHD features two inequalities that a quantum field, squeezed or not, violates, thus non-classicality of a quadrature does not depend on squeezing.…”