Probe susceptibility of a strongly driven qubit

Gilberto Aparecido Prataviera, Salomon Sylvain Mizrahi, V. V. Dodonov +1 more

We analyze the effects of a reservoir having a generic spectrum (colored noise) on the index of refraction of a system of strongly driven two-level atoms (gas) probed by a weak field. We show that for high Rabi frequencies, $\ensuremath{\Omega},$ a simple analytic expression results for the susceptibility function (with respect to the probe) when $\ensuremath{\nu}\ensuremath{\approx}\ensuremath{\Omega},$ where $\ensuremath{\nu}$ is the detuning between driving and probe fields frequencies. Several distinct features are revealed in that function when compared to the one resulting from a reservoir with a white-noise spectrum (atom-vacuum coupling). We also show that the Mach-Zehnder interferometry could permit distinguishing between the two kinds of spectra and we point out the sensitive dependence of the index of refraction of the atomic gas on $\ensuremath{\Omega}$ and find a signature for the non-Markovian evolution.

健太 武田, Kenta Takeda, 純 神岡 +15 more

Ji-Bing Liu, Na Liu, Chuan-Jia Shan +2 more

In this paper, we theoretically investigate the propagation properties of probe and mixing fields in a quantum well waveguide. This waveguide is driven by two strong control (pumping and coupling) fields and a weak probe field. Under appropriate parameters condition, the electron spin coherence can suppress the absorption and enhance the nonlinear susceptibilities of the probe (or mixing) field. This study reveals that probe (or mixing) field can form soliton pairs and propagate in the quantum well waveguide with slow group velocity. We also study the soliton collision and dynamics evolution. The results show that the propagation of soliton can be strongly modified by the electron spin coherence.

A. S. Usoltsev, L. V. Gerasimov, A. D. Manukhova +2 more

We present a microscopic analysis and evaluation of the dielectric susceptibility of a dielectric medium consisting of vector-type two-energy-level atoms responding on a weak probe mode when the atoms are driven by a strong coherent field. Each atom, in an environment of others, exists as a quasiparticle further structuring a bulk medium. In a limit of dilute atomic gas, the dynamics of each atom follows the Mollow-type nonlinear excitation regime, and the medium susceptibility collectivizes the individual atomic responses to the probe mode. We outline how the collective dynamics can be interpolated up to a dense medium, and we argue from general positions that in such a medium the optical nonlinearity and, in particular, its parametric part could be significantly magnified by manipulating both the coherent pump and the sample density. That indicates certain limitations for potential capabilities of quantum communication protocols utilizing the entangled photons, created by a parametric process, as a main resource of quantum correlations.

J. Stehlik, Yuliya Dovzhenko, J. R. Petta +2 more