Bunching and antibunching of de-excited atoms leaving a micromaser

Günter Manzke, W. Vogel, D.‐G. Welsch

Ulrike Herzog

Explicit expressions are derived for calculating the two-time coincidence probability density, the Mandel Q parameter of the counting statistics, and the waiting-time distribution between detector clicks for the detection of de-excited atoms leaving a micromaser with Poissonian pumping. The procedure is illustrated by applying it to the simplest trapped micromaser state for which all results can be obtained analytically. Moreover, by making use of a symmetry relation which determines the properties of the time-dependent micromaser master equation solution, it is shown that in the stationary regime for negligible thermal photon number the normalized two-time intensity correlation function of the cavity field with respect to a given time difference is equal to the normalized two-time coincidence probability density of detecting two de-excited atoms with the same time difference at the exit of the micromaser.

Federico Casagrande, Berthold‐Georg Englert, Pavel Lougovski +3 more

A micromaser, where an additional classical field strongly drives the atoms crossing the cavity, provides an example of a solvable open quantum system with pumping and dissipation. The coherent time evolution consists in cavity field displacements correlated with atomic internal states, a different entanglement than the usual Jaynes-Cummings interaction. We provide analytical results and phase space descriptions via the quantum characteristic function. We illustrate bunching and antibunching effects at steady state in atom pair correlation measurements, where the control parameter is simply the atomic velocity.

John Martin, Thierry Bastin

Sebastian Wolf, Stefan Richter, Joachim von Zanthier +1 more

Photon statistics divides light sources into three different categories, characterized by bunched, antibunched, or uncorrelated photon arrival times. Single atoms, ions, molecules, or solid state emitters display antibunching of photons, while classical thermal sources exhibit photon bunching. Here we demonstrate a light source in free space, where the photon statistics depends on the direction of observation, undergoing a continuous crossover between photon bunching and antibunching. We employ two trapped ions, observe their fluorescence under continuous laser light excitation, and record spatially resolved the autocorrelation function g^{(2)}(τ) with a movable Hanbury Brown and Twiss detector. Varying the detector position we find a minimum value for antibunching, g^{(2)}(0)=0.60(5) and a maximum of g^{(2)}(0)=1.46(8) for bunching, demonstrating that this source radiates fundamentally different types of light alike. The observed variation of the autocorrelation function is understood in the Dicke model from which the observed maximum and minimum values can be modeled, taking independently measured experimental parameters into account.

Camilo Alberto Arancibia-Bulnes, H. M. Moya-Cessa, Javier J. Sanchez-Mondragon +1 more