Topic
Atomic coherence
About: Atomic coherence is a research topic. Over the lifetime, 877 publications have been published within this topic receiving 29395 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: In this paper, it was shown that the fundamental precision of the mapping is near the standard quantum limit on phase estimation for a coherent spin state, where φ = 1/ √ N,w hereN is the number of atoms.
Abstract: cold-atom 87 Rb Raman laser. We show theoretically that the fundamental precision of the mapping is near the standard quantum limit on phase estimation for a coherent spin state, �φ = 1/ √ N ,w hereN is the number of atoms. The associated characteristic measurement time scale τW ∝ 1/N is collectively enhanced. The nondemolition nature of the measurement is characterized by only 0.5 photon recoils deposited per atom due to optical repumping in a time τW. We experimentally realize conditional Ramsey spectroscopy in our superradiant Raman laser, compare the results to the predicted precision, and study the mapping in the presence of decoherence, far from the steady-state conditions previously considered. Finally, we demonstrate a hybrid mode of operation in which the laser is repeatedly toggled between active and passive sensing.
25 citations
TL;DR: In this article, the collective radiative behavior of three level atoms with two degenerate levels in the ground state was investigated, with particular emphasis on the role of ground state atomic coherence.
25 citations
TL;DR: In this article, the authors show that the adiabatic dynamics of a Bose-Einstein condensate in a double-well potential can be described in terms of a dark variable resulting from the combination of the population imbalance and the spatial atomic coherence between the two wells.
Abstract: We show that the adiabatic dynamics of a Bose-Einstein condensate (BEC) in a double-well potential can be described in terms of a dark variable resulting from the combination of the population imbalance and the spatial atomic coherence between the two wells. By means of this dark variable, we extend, to the nonlinear matter-wave case, the recent proposal by Vitanov and Shore [Phys. Rev. A 73, 053402 (2006)] on adiabatic passage techniques to coherently control the population of two internal levels of an atom or molecule. We investigate the conditions to adiabatically split or transport a BEC as well as to prepare an adiabatic self-trapping state by the optimal delayed temporal variation of the tunneling rate via either the energy bias between the two wells or the BEC nonlinearity. The emergence of nonlinear eigenstates and unstable stationary solutions of the system as well as their role in the breaking down of the adiabatic dynamics is investigated in detail.
25 citations
TL;DR: In this paper, a quantum memory scheme based on controlled de-and rephasing of atomic coherence of a nonresonant, inhomogeneously broadened Raman transition is examined.
Abstract: We examine a quantum memory scheme based on controlled de- and rephasing of atomic coherence of a nonresonant, inhomogeneously broadened Raman transition. We show that it generalizes the physical conditions for time-reversible interaction between light and atomic ensembles in the case of strong fields and nonlinear interactions. Furthermore, assuming weak input fields, we develop a unified framework for realizations exploiting either controlled reversible inhomogeneous broadening or atomic frequency combs, and discuss new aspects of the storage and manipulation of quantum states.
25 citations
Posted Content•
TL;DR: In this paper, the authors investigated light induced absorption with population inversion and amplification without inversion (LWI) in a coherently prepared closed three level V -type system.
Abstract: Light induced absorption with population inversion and amplification without population inversion (LWI) in a coherently prepared closed three level V - type system are investigated. This study is performed from the point of view of a two color dressed state basis. Both of these processes are possible due to atomic coherence and quantum interference contrary to simple intuitive predictions. Merely on physical basis, one would expect a complementary process to the amplification without inversion. We believe that absorption in the presence of population inversion found in the dressed state picture utilized in this study, constitutes such a process.
Novel approximate analytic time dependent solutions, for coherences and populations are obtained, and are compared with full numerical solutions exhibiting excellent agreement. Steady state quantities are also calculated, and the conditions under which the system exhibits absorption and gain with and without inversion, in the dressed state representation are derived. It is found that for a weak probe laser field absorption with inversion and amplification without inversion may occur, for a range of system parameters.
24 citations