The field of quantum optomechanics is newly grooming research field, availed good attention in the last couple of years. Here, we theoretically study the system of optomechanics containing a two-level atom, which is coupled to the cavity field, and driven coherently by external fields. Analytical results for the system’s operator dynamics, steady state solutions and transmissivity of optomechanical system are calculated. Transmission (optical response) from the optomechanical system shows some useful information about the current optomechanical system. Particularly, [Formula: see text] = [Formula: see text]-g0([Formula: see text] + [Formula: see text]) is a crucial quantity in optomechanics, focused as main parameters in this paper. Optical transmission is studied in two regions. The first region (case) (i) when [Formula: see text] = [Formula: see text] - [Formula: see text], and in second region (case), (ii) [Formula: see text] = [Formula: see text] + [Formula: see text]. The transmission is examined and discussed with respect to the mechanical frequency of the oscillating mirror.
The field of quantum optomechanics is newly grooming research field, availed good attention in the last couple of years. Here, we theoretically study the system of optomechanics containing a two-level atom, which is coupled to the cavity field, and driven coherently by external fields. Analytical results for the system’s operator dynamics, steady state solutions and transmissivity of optomechanical system are calculated. Transmission (optical response) from the optomechanical system shows some useful information about the current optomechanical system. Particularly, [Formula: see text] = [Formula: see text]-g0([Formula: see text] + [Formula: see text]) is a crucial quantity in optomechanics, focused as main parameters in this paper. Optical transmission is studied in two regions. The first region (case) (i) when [Formula: see text] = [Formula: see text] - [Formula: see text], and in second region (case), (ii) [Formula: see text] = [Formula: see text] + [Formula: see text]. The transmission is examined and discussed with respect to the mechanical frequency of the oscillating mirror.
Abstract In this article, we theoretically investigate a quadratically coupled optomechanical system with a two-level atom. At steady-state, we examine the variation of transmission intensity with various parameters of the system as well as investigate the transmission in lower/upper sidebands. Moreover, taking into account the quantum fluctuations, we extend our investigation towards the study of quantum coherence for the optomechanical system. The result shows that the coherence inside the proposed cavity can be efficiently controlled by varying atom-to-photon coupling and modified optical detuning. We also discuss and provide a physical explanation of why the atomic coherence can surpass the optical and mechanical ones.
With the widely application and development of the mechanical system and optical microcavity, the strong coupling between mirror and cavityfield in the system of cavity optomechanics，that make the optomechanical system become an important platform which is used to inspect macroscopic quantum phenomena and text quantum theory, so that become a new research hot spot．At the same time，for cavity opto-mechanics，there are important application prospect in gravitational waves detection, infinitesimal is placement and the precision measurement of the quality and so on，therefore the study of cavity opto-mechanics has the profound significance.This article first introduced the optical mechanical cavity, and then examines the atomic population is poor.We found that the difference of atomic population with the time evolution law of motion state of the mirror is very sensitive, if the initial state of the mirror as the coherent state, the atomic population difference will collapse and reply phenomenon, collapse time and cycle depends on the cavity photon number and average number of vibrator.Finally studied the optical mechanical two-level atomic emission spectrum characteristics of cavity.
This paper investigates a coupled cavity optomechanical system consisting of two Fabry-Perot cavities and the two cavities are coupled via an optical fiber.Every cavity is made of one fixed mirror and a movable mirror,and the movable mirror can be regarded as a mechanical oscillators.Meanwhile,the two cavity modes are driven by classical laser fields.So,the interaction is inevitable between cavities,cavity and moving mirror,cavity and classical field.Firstly,in order to eliminate the two cavity fields,an effective Hamiltonian of the two phonon modes is derived by means of picture transformation,adiabatic eliminating,and rotating wave approximation ignoring the high frequency items,etc.Secondly,if the two mechanical oscillators initially are in coherent states,the coupled mechanical oscillators can be used to transmit state.Finally,in order to verify the analytical result,the fidelity of quantum state is numevically simulated,the result shows that the quantum state can be transferred periodically between the two mechanical oscillators,which is the same as the analytical result.
We study the optical bistability and dynamics in a hybrid optomechanical system, where the cavity mode is coupled to the mechanical resonator via radiation pressure and to a two-level atom via the Jaynes–Cummings coupling. The nonlinearity due to optomechanical coupling and the addition of an atom leads to bistable behaviors of the steady-state intracavity photon number and atomic population inversion. We show that the optical bistability can be effectively controlled by the Rabi frequency of the atomic driving field, the cavity–atom coupling strength, and the amplitude and frequency of the cavity pump field. Moreover, the effects of different initial conditions of the cavity field and the amplitude of the cavity pump field on the dynamics of the system also have been discussed.
In this paper, optical bistability in hybrid optomechanical systems consisting of two cavities (optomechanical and conventional) coupled to each other, which contain quantum dot molecules (QDMs), is investigated and compared. For this purpose, two different configurations are studied: in the first configuration, the quantum dot molecules (QDMs) are inside the optomechanical cavity, and in the second configuration, the quantum dot molecules are inside the conventional cavity. To calculate the dynamics of the system operators, the Heisenberg-Langevin approach is used under the mean field approximation. To achieve the phenomenon of optical bistability, which is used in optical switches and optical memories, the dynamic equations of the system are solved in a steady state. The effect of the system's physical parameters, including the detuning, the number of quantum dot molecules, and the tunneling intensity of the external field, on the phenomenon of optical bistability is studied. In addition, the switching threshold and the width of the optical bistability region in two different configurations are compared. Considering that the phenomenon of optical bistability can have potential applications in all-optical switches, optical transistors, quantum computing, and quantum communication, the obtained results can be useful for the mentioned applications and system optimization.
In this paper, the optical nonreciprocal phenomena in double optomechanical systems with quadratic coupling are studied. Our model belongs to an optomechanical system in which three coupling modes coexist, that is, the two cavity fields are coupled with the mechanical oscillator at the same time and the couplings are in the form of quadratic interactions. In addition, there is a linear coupling mode between the two cavity fields. In the entire system, each cavity field is effectively coupled by a control field and a probe field simultaneously. The expression of the transmission coefficient of the probe field is obtained by solving the dynamic evolution equation satisfied by the system. Using numerical analysis, we analyze the change in transmission coefficient of the probe field under the conditions of different physical parameters. The results show that we can realize optical nonreciprocal transmission in this system. Appropriate choices about physical parameters can achieve perfect nonreciprocity. Our theoretical scheme to realize optical nonreciprocal transmission in a double optomechanical system provides a theoretical basis for optical circulators, cyclic amplifiers and directional amplifiers.