May E. Kim

Distortion free pulse delay system using a pair of tunable white light cavities

Recently, a tunable bandwidth white light cavity (WLC) was demonstrated by using an anomalously dispersive intra-cavity medium to adjust a cavity linewidth without reducing the cavity buildup factor [G.S. Pati et al., Phys. Rev. Lett. 99, 133601 (2007)]. In this paper, we show theoretically how such a WLC can be used to realize a distortion-free delay system for a data pulse. The system consists of two WLCs placed in series. Once the pulse has passed through them, the fast-light media in both WLCs are deactivated, so that each of these now acts as a very high reflectivity mirror. The data pulse bounces around between these mirrors, undergoing negligible attenuation per pass. The trapped pulse can be released by activating the fast-light medium in either WLC. Numerical simulations show that such a system can far exceed the delay-bandwidth constraint encountered in a typical data buffer employing slow light. We also show that the pulse remains virtually undistorted during the process.

Effects of non-idealities and quantization of the center of mass motion on symmetric and asymmetric collective states in a collective state atomic interferometer

We investigate the behavior of an ensemble of non-interacting, identical atoms excited by a laser. In general, the -th atom sees a Rabi frequency , an initial position dependent laser phase , and a motion induced Doppler shift of . When or is distinct for each atom, the system evolves into a superposition of intercoupled states, of which there are symmetric and asymmetric collective states. For a collective state atomic interferometer (COSAIN), we recently proposed, it is important to understand the behavior of all the collective states under various conditions. In this paper, we show how to formulate the properties of these states under various non-idealities, and use this formulation to understand the dynamics thereof. We also consider the effect of treating the center of mass degree of freedom of the atoms quantum mechanically on the description of the collective states, illustrating that it is indeed possible to construct a generalized collective state, as needed for the COSAIN, when each atom is assumed to be in a localized wave packet. The analysis presented in this paper is important for understanding the dynamics of the COSAIN, and will help advance the analysis and optimization of spin squeezing in the presence of practically unavoidable non-idealities as well as in the domain where the center of mass motion of the atoms is quantized.

N -atom collective-state atomic interferometer with ultrahigh Compton frequency and ultrashort de Broglie wavelength, with N reduction in fringe width

We describe a collective state atomic interferometer (COSAIN) with the signal fringe as a function of phase-difference or rotation narrowed by

An N-atom Collective State Atomic Clock with Root-N Fold Increase in Effective Frequency and Root-N Fold Reduction in Fringe Width

\sqrt{N}

Rydberg assisted light shift imbalance induced blockade in an atomic ensemble

compared to a conventional interferometer -

Ultra-high Compton frequency atomic interferometric gyroscope using collective states

N

Rydberg excitation assisted light shift blockade in Rb atoms for realizing a collective state quantum bit and quantum memory

being the number of atoms - without entanglement. This effect arises from the interferences among collective states, and is a manifestation of interference at a Compton frequency of ten nonillion Hz, or a de Broglie wavelength of ten attometer, for

Generalized Collective States and Their Role in a Collective State Atomic Interferometer and Atomic Clock

N=10^6

A Schroedinger Cat Matter Wave Gyroscope Using Collective Excitation of Atomic Ensembles

and

Collective State Atomic Clock: Experimental Investigation and Application to Spin-Squeezing

v = 300 m/s