检索结果-南通市图书馆

Fano profile in a novel double cavity optomechanical system with harmonically bound mirrors

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2020年第9期72卷 96-103页

作者： Vaibhav N Prakash aranya b bhattacherjee School of Physical Sciences Jawaharlal Nehru UniversityNew Delhi-110067India Department of Physics Birla Institute of Technology and SciencePilaniHyderabad CampusHyderabad一50007&India

We investigate a double cavity optomechanical system generating single and double Fano resonance(multi-Fano). by altering a single parameter, the tunnelling rate g of the middle mirror, we are able to switch between single and double Fano line shapes. The first spectral line shape is stronger in the case of multi-Fano than in the case of single Fano. Also the behaviour of the steady state value of the displacement of the middle mirror, with respect to g, heavily influences the behaviour of double Fano lines in our scheme. This tunability along with using a single pump and signal/probe laser has an added advantage in situations where only low power consumption is available.

关键词： optomechanics double Fano resonance optical switch single Fano resonance

Non-equilibrium Dynamics of an Optomechanical Dicke Model

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2015年第7期64卷 39-46页

作者： Kamanasish Debnath aranya b.bhattacherjee Institute of Applied Sciences Amity University School of Physical Sciences Jawaharlal Nehru University

Motivated by the experimental realization of Dicke model in optical cavities, we model an optomechanical system consisting of two-level bEC atoms with transverse pumping. We investigate the transition from normal and inverted state to the superradiant phase through a detailed study of the phase portraits of the system. The rich phase portraits generated by analytical arguments display two types of superradiant phases, regions of coexistence and some portion determining the persistent oscillations. We study the time evolution of the system from any phase and discuss the role of mirror frequency in reaching their attractors. Further, we add an external mechanical pump to the mirror which is capable of changing the mirror frequency through radiation pressure and study the impact of the pump on the phase portraits and the dynamics of the system. We find the external mirror frequency changing the phase portraits and even shifting the critical transition point, thereby predicting a system with controllable phase transition.

关键词： Dicke model optomechanics bose–Einstein condensati

Dynamical Casimir effect in superradiant light scattering by bose Einstein condensate in an optomechanical cavity

在线全文

学校读者我要写书评

暂无评论

Chinese Physics b 2014年第2期23卷 151-160页

作者： Sonam Mahajan Neha Aggarwal aranya b bhattacherjee ManMohan Department of Physics and Astrophysics University of Delhi Department of Physics ARSD CollegeUniversity of Delhi (South Campus) School of Physical Sciences Jawaharlal Nehru University

We investigate the effects of dynamical Casimir effect in superradiant light scattering by bose-Einstein condensate in an optomechanical cavity. The system is studied using both classical and quantized mirror motions. The cavity frequency is harmonically modulated in time for both the cases. The main quantity of interest is the number of intracavity scattered photons. The system has been investigated under the weak and strong modulations. It has been observed that the amplitude of the scattered photons is more for the classical mirror motion than the quantized mirror motion. Also, initially, the amplitude of scattered photons is high for lower modulation amplitude than higher modulation amplitude. We also found that the behavior of the plots are similar under strong and weak modulations for the quantized mirror motion.

关键词： bose-Einstein condensates dynamical Casimir effect superradiant light scattering optomechan- ical cavity

Excitations of optomechanically driven bose Einstein condensates in a cavity: Photodetection measurements

在线全文

学校读者我要写书评

暂无评论

Chinese Physics b 2014年第10期23卷 32-44页

作者： Neha Aggarwal Sonam Mahajan aranya b.bhattacherjee Man Mohan Department of Physics and Astrophysics University of Delhi Department of Physics ARSD College University of Delhi (South Campus) School of Physical Sciences Jawaharlal Nehru University

We present a detailed study to analyze the Dicke quantum phase transition within the thermodynamic limit for an optomechanically driven bose-Einstein condensate in a cavity. The photodetection-based quantum optical measurements have been performed to study the dynamics and excitations of this optomechanical Dicke system. For this, we discuss the eigenvalue analysis, fluorescence spectrum and the homodyne spectrum of the system. It has been shown that the normal phase is negligibly affected by the mechanical mode of the mirror while it has a significant effect in the superradiant phase. We have observed that the eigenvalues and the spectra both exhibit distinct features that can be identified with the photonic, atomic and phononic branches. In the fluorescence spectra, we further observe an asymmetric coherent energy exchange between the three degrees of freedom of the system in the superradiant phase arising as a result of optomechanical interaction and bloch-Siegert shift.

关键词： optomechanical cavity bose-Einstein condensates quantum phase transition