• Chinese Optics Letters
  • Vol. 19, Issue 12, 122701 (2021)
E. Ghasemian and M. K. Tavassoly*
Author Affiliations
  • Optic and Laser Group, Faculty of Physics, Yazd University, Yazd, Iran
  • show less

    Abstract

    We investigate the dynamics of a system that consists of ultra-cold three-level atoms interacting with radiation fields. We derive the analytical expressions for the population dynamics of the system, particularly, in the presence and absence of nonlinear collisions by considering the rotating wave approximation (RWA). We also reanalyze the dynamics of the system beyond RWA and obtain the state vector of the system to study and compare the time behavior of population inversion. Our results show that the system undergoes two pure quantum phenomena, i.e., the collapse–revival and macroscopic quantum self-trapping due to nonlinear collisional interactions. The occurrence of such phenomena strongly depends on the number of atoms in the system and also the ratio of interaction strengths in the considered system. Finally, we show that the result of the perturbed time evolution operator up to the second-order is in agreement with the numerical solution of the Schrödinger equation. The results presented in the paper may be useful for the design of devices that produce a coherent beam of bosonic atoms known as an atom laser.

    1. Introduction

    Nowadays a great deal of attention has been focused on the design of a device that produces a coherent beam of bosonic atoms known as an atom laser. Such devices are applicable in atom optics for various purposes, i.e., atom lithography, nano fabrication, and fundamental tests of quantum mechanics such as those involving atom interferometry[1]. The experimental realization of the Bose–Einstein condensate (BEC) results in the fast progress of atom optics due to the fact that a macroscopic number of atoms can be condensed in the ground state of an atomic trap that occupies a single quantum-mechanical state[2,3]. One of the most challenging problems in real many-particle systems is the coherent control of the interaction between the relevant particles.

    Copy Citation Text
    E. Ghasemian, M. K. Tavassoly. Population dynamics of ultra-cold atoms interacting with radiation fields in the presence of inter-atomic collisions[J]. Chinese Optics Letters, 2021, 19(12): 122701
    Download Citation
    Category: Quantum Optics and Quantum Information
    Received: Apr. 16, 2021
    Accepted: Jun. 18, 2021
    Posted: Jun. 21, 2021
    Published Online: Sep. 9, 2021
    The Author Email: M. K. Tavassoly (mktavassoly@yazd.ac.ir)