Manipulation of optical memory bits in atomic vapors and Bose-Einstein condensates

激光解吸、缓冲气体冷却的 C$_{60}$ 中全对比度二十面体玻色–爱因斯坦统计的观测

Observation of full contrast icosahedral Bose-Einstein statistics in laser desorbed, buffer gas cooled C$_{60}$

本文利用激光解吸缓冲气体冷却源和红外光谱观测 $^{12}$C$_{60}$ 的 R(J=0–29) 转动序列，揭示其二十面体对称性导致的全对比度玻色–爱因斯坦统计。

Driving the slow-light soliton by controlling laser field

In the framework of the nonlinear $Λ$-model we investigate propagation of a slow-light soliton in atomic vapors and Bose-Einstein condensates. The velocity of the slow-light soliton is controlled by a time-dependent background field created by a controlling laser. For a fairly arbitrary time dependence of the field we find the dynamics of the slow-light soliton inside the medium. We provide an analytical description for the nonlinear dependence of the velocity of the signal on the controlling field. If the background field is turned off at some moment of time, the signal stops. We find the loc…

Theory of slow-light solitons

In the framework of the nonlinear $Λ$-model we investigate propagation of solitons in atomic vapors and Bose-Einstein condensates. We show how the complicated nonlinear interplay between fast solitons and slow-light solitons in the $Λ$-type media points to the possibility to create optical gates and, thus, to control the optical transparency of the $Λ$-type media. We provide an exact analytic description of decelerating, stopping and re-accelerating of slow-light solitons in atomic media in the nonadiabatic regime. Dynamical control over slow-light solitons is realized via a controlling field …

Observation of the Bogoliubov dispersion relation in a fluid of light

Quantum fluids of light are photonic counterpart to atomic Bose gases and are attracting increasing interest for probing many-body physics quantum phenomena such as superfluidity. Two different configurations are commonly used: the confined geometry where a nonlinear material is fixed inside an optical cavity, and the propagating geometry where the propagation direction plays the role of an effective time for the system. The observation of the dispersion relation for elementary excitations in a photon fluid has proved to be a difficult task in both configurations with few experimental real iza…

原子激光频率梳光谱的蒙特卡罗模拟

Monte-Carlo simulation for the frequency comb spectrum of an atom laser

本文提出基于虚时间的粒子数守恒量子场论，通过复值正交分解与蒙特卡罗采样方法，数值模拟了超冷原子激光的频率梳光谱及其随温度和陷阱频率的变化。

The eight-port homodyne detector: the effect of imperfections on quantum random number generation and on detection of quadratures

The eight-port homodyne detector is an optical circuit designed to perform the monitoring of two quadratures of an optical field, the signal. By using quantum Bose fields and quantum stochastic calculus, we give a complete quantum description of this apparatus, when used as quadrature detector in continuous time. We can treat either the travelling waves in the optical circuit, either the observables involved in the detection part: two couples of photodiodes, postprocessing of the output currents. The analysis includes imperfections, such as not perfectly balanced beam splitters, detector effic…

Squeezed-light-enhanced atom interferometry below the standard quantum limit

We investigate the prospect of enhancing the phase sensitivity of atom interferometers in the Mach-Zehnder configuration with squeezed light. Ultimately, this enhancement is achieved by transferring the quantum state of squeezed light to one or more of the atomic input beams, thereby allowing operation below the standard quantum limit. We analyze in detail three specific schemes that utilize (1) single-mode squeezed optical vacuum (i.e. low frequency squeezing), (2) two-mode squeezed optical vacuum (i.e. high frequency squeezing) transferred to both atomic inputs, and (3) two-mode squeezed opt…