Searcharxiv⌕ Search

arXiv subjects

Aranya B Bhattacherjee

Publications and source records attributed to Aranya B Bhattacherjee.

At least 19 recordsLinked to original sources
arXiv2022

Enhanced Photon Squeezing in Two-Photon Dicke Model

We explore the phenomena of quadrature squeezing of photons in the Two-Photon Dicke Model under the mean-field approximation in the thermodynamic limit. The strength of photon squeezing is maximized in the region where the coupling strength is of the same order of magnitude as one of the fundamental frequency of the system. This particular region is termed as the unbounded region. The squeezing of the photonic quadratures can be observed only in the superradiant phase where the squeezing is well beyond the standard quantum limit both near the quantum critical point as well as the unbounded region. However, prolonged squeezing is only obtained in the latter case. Furthermore, we explore the critical behavior of photon squeezing near the unbounded region.

quant-ph↗
arXiv2021

Far-Infrared frequency mode conversion using bulk acoustic phonon modes

The ability to design, fabricate and control systems that can convert photons with dissimilar frequencies has technological implications in classical as well as quantum communications. Laser heating and thermal-mechanical motion in conventional micro/nanoscale optomechanical systems hamper the use of these systems in quantum information processing networks. In contrast, we propose an unconventional system comprising of a bulk quartz crystal placed within a Fabry-Perot cavity. The pumping laser is in the far-infrared region. We explore the possibility of efficient mode conversion between two optical modes supported by the system, mediated by the bulk acoustic phonons of the quartz crystal. Unlike the earlier optomechanical systems, the dark mode in our proposed system is not decoupled from the mechanical mode and yet it enables the efficient mode conversion. The novel results found in our study can be used to harness the dark state for quantum state transfer. The proposed system is robust against excessive heating.

quant-ph↗
arXiv2021

Role of Dissipation on the Stability of a Parametrically Driven Quantum Harmonic Oscillator

We study the dissipative dynamics of a single quantum harmonic oscillator subjected to a parametric driving with in an effective Hamiltonian approach. Using Liouville von Neumann approach, we show that the time evolution of a parametrically driven dissipative quantum oscillator has a strong connection with the classical damped Mathieu equation. Based on the numerical analysis of the Monodromy matrix, we demonstrate that the dynamical instability generated by the parametric driving are reduced by the effect of dissipation. Further, we obtain a closed relationship between the localization of the Wigner function and the stability of the damped Mathieu equation.

quant-ph↗
arXiv2021

Optical response properties of hybrid electro-opto-mechanical system interacting with a qubit

We investigate the optical response of a hybrid electro-optomechanical system interacting with a qubit. In our experimentally feasible system, tunable all-optical-switching, double-optomechanically induced transparency (OMIT) and optomechanically induced absorption (OMIA) can be realized. The proposed system is also shown to generate anomalous dispersion. Based on our theoretical results, we provide a tunable switch between OMIT and OMIA of the probe field by manipulating the relevant system parameters. Also, the normal-mode-splitting (NMS) effect induced by the interactions between the subsystems are discussed in detail and the effects of varying the interactions on the NMS are clarified. These rich optical properties of the probe field may provide a promising platform for controllable all-optical-switch and various other quantum photonic devices.

quant-ph↗
arXiv2020

Continuous-Variable Deep Quantum Neural Networks for Flexible Learning of Structured Classical Information

Quantum computation using optical modes has been well-established in its ability to construct deep neural networks. These networks have been shown to be flexible both architecturally as well as in terms of the type of data being processed. We leverage this property of the Continuous-Variable (CV) model to construct stacked single mode networks that are shown to learn structured classical information, while placing no restrictions on the size of the network, and at the same time maintaining it's complexity. The hallmark of the CV model is its ability to forge non-linear functions using a set of gates that allows it to remain completely unitary. The proposed model exemplifies that the appropriate photonic hardware can be integrated with present day optical communication systems to meet our information processing requirements. In this paper, using the Strawberry Fields software library on the MNIST dataset of hand-written digits, we demonstrate the adaptability of the network to learn classical information to fidelities of greater than 99.98%

quant-ph↗
arXiv2020

Quantum Optical Response of a Hybrid Optomechanical Device embedded with a Qubit

We theoretically investigate the optical response in a hybrid quantum optomechanical system consisting of two optically coupled micro-cavities in which a two-level system (qubit) is embedded on a movable membrane. The qubit can either be a defect which interacts with the mechanical oscillator via the linear Jaynes-Cummings interaction or a superconducting charge qubit coupled with the mechanical mode via nonlinear interaction. We find that coherent perfect transmission (CPT), coherent perfect synthesis (CPS) and optomechanically induced absorption (OMIA) can be generated by suitably adjusting the system parameters. We find that the qubit and its interaction with the mechanical oscillator emerges as a new handle to control these quantum optical properties. The presence of the qubit results in four points where CPT and CPS can be realized compared to the pure optomechanical case (i.e. in the absence of qubit) where only three points are attained. This shows that the presence of the qubit gives us more flexibility in choosing the appropriate parameter regime where CPT and CPS can be attained and controlled. We also find that OMIA shows three distinct peaks both in the linear and nonlinear cases. In the absence of the qubit, OMIA is converted to optomechanically induced transmission (OMIT). An increase in in the qubit decay rate also shows a transition from OMIA to OMIT. Our study reveals that the optical response of the nonlinear case is relatively rapid (more sensitive) compared to the linear case to changes in the system parameters. This demonstrates the potential use of this hybrid system in designing tunable all-optical-switch and photon-router both of which forms an important element of a quantum information network.

quant-ph↗
arXiv2019

Fano profile in double cavity optomechanical system with harmonically bound mirrors

We investigate a double cavity optomechanical system(OMS) generating single and double Fano resonance(multi Fano). By altering a single parameter, the tunneling 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 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.

quant-ph↗
arXiv2019

Optomechanical control of mode conversion in a hybrid semiconductor microcavity containing a quantum dot

The future of quantum communication systems and quantum networks heavily rely on the ability to fabricate and coherently control the conversion of photons between different modes based on a solid-state plateform. In this work, we propose and theoretically investigate a scheme to optomechanically control coherent mode conversion of optical photons by utilizing two optically coupled hybrid semiconductor microcavities containing a quantum dot (QD). One of the microcavity is pumped by an external laser and the second cavity is driven by light emitted by the QD that is embedded in the interface separating the two microcavities. The semiconductor microcavities can be fabricated using distributed Bragg reflectors (DBR) and can be made movable. We have demonstrated that photon-mode-conversion efficiency can be coherently manipulated by the optomechanical mode under appropriate conditions.

quant-ph↗
arXiv2018

Negative effective mass, optical multistability and Fano line-shape control via mode tunneling in double cavity optomechanical system

We theoretically investigate the optical and mechanical properties of a double cavity optomechanical system with one stationary and two harmonically bound mirrors. We show that it is possible for the mechanical mirrors in this system to posses negative effective mass. Working within the strong coupling and the resolved sideband regime, we show that the displacement of the middle resonator is multistable under certain constrains. We also point to the existence of optomechanically induced absorption (OMIA) and Fano resonance. Owing to the negative effective mass, our scheme can be exploited in the study of quantum optomechanical metamaterials.

quant-ph↗
arXiv2018

Controllable nonlinear effects in a hybrid optomechanical semiconductor microcavity containing a quantum dot and Kerr medium

We theoretically investigate the nonlinear effects in a hybrid quantum optomechanical system consisting of two optically coupled semiconductor microcavities containing a quantum dot and a Kerr nonlinear substrate.The steady state behavior of the mean intracavity optical field demonstrates that the system can be used as an all optical switch. We further investigate the spectrum of small fluctuations in the mechanical displacement of the movable distributed Bragg reflectors (DBR) and observe that normal mode splitting (NMS) takes place for high Kerr nonlinearity and pump power. In addition, we have shown that steady state of the system exhibits two possible bipartite entanglements by proper tuning of the system parameters. The entanglement results suggest that the proposed system has the potential to be used in quantum communication platform. Our work demonstrates that the Kerr-nonlinearity can effectively control the optical properties of the hybrid system, which can be used to design efficient optical devices.

cond-mat.mes-hall↗
arXiv2018

Photon statistics of radiation emitted by two quantum wells embedded in two optically coupled semiconductor microcavities

We study theoretically the photon statistics of the field emitted from two optically coupled semiconductor microcavities each containing a quantum well. The emission is determined by the interplay between exciton-photon coupling in each quantum well and internal interaction between the two optically coupled microcavities. A high degree of coherent control and tunability via the quantum well-cavity coupling strength and photon tunneling over the photon statistics of the transmitted field can be achieved. We demonstrate that the optical property of radiation emitted by one quantum well can be controlled by the properties of the second quantum well. This result has the potential to be used in quantum information processing. We show that the exciton-photon coupling influences the polariton resonances in the intensity spectrum of the transmitted field. The results obtained in this investigation has the potential to be used for designing efficient controllable all-optical switch and high sensitive optical sensor.

cond-mat.mes-hall↗
arXiv2017

Controllable optical bistability and Fano line shape in a hybrid optomechanical system assisted by Kerr medium: Possibility of all optical switching

We theoretically analyze the optical and optomechanical nonlinearity present in a hybrid system consisting of a quantum dot(QD) coupled to an optomechanical cavity in the presence of a nonlinear Kerr medium, and show that this hybrid system can be used as an all optical switch. A high degree of control and tunability via the QD-cavity coupling strength, the Kerr and the optomechanical nonlinearity over the bistable behavior shown by the mean intracavity optical field and the power transmission of the weak probe field can be achieved.The results obtained in this investigation has the potential to be used for designing efficient all-optical switch and high sensitive sensors for use in Telecom systems.

quant-ph↗
arXiv2017

Spin and tunneling dynamics in an asymmetrical double quantum dot with spin - orbit coupling

In this article we study the spin and tunneling dynamics as a function of magnetic field in a one-dimensional GaAs double quantum dot with both the Dresselhaus and Rashba spin-orbit coupling. In particular we consider different spatial widths for the spin-up and spin-down electronic states. We find that the spin dynamics is a superposition of slow as well as fast Rabi oscillations. It is found that the Rashba interaction strength as well as the external magnetic field strongly modifies the slow Rabi oscillations which is particularly useful for single qubit manipulation for possible quantum computer applications.

cond-mat.mes-hall↗
arXiv2016

Spin squeezing and Quantum Fisher Information in the Jaynes-Cummings Dicke Model

We investigate spin squeezing (SS) and the quantum Fisher information (QFI) for the Jaynes-Cummings Dicke (JC-Dicke) model in a two component atomic Bose-Einstein condensate (BEC) inside an optical cavity. Analytical expressions for spin squeezing and the reciprocal of the quantum Fisher information per particle (RMQFI) are derived using the frozen spin approximation. It is shown that in the superradiant phase near the critical point, maximum squeezing and maximum quantum entanglement occurs. The present study is relevant to quantum information processing and precision spectroscopy.

cond-mat.quant-gas↗
arXiv2015

Influence of periodically modulated cavity field on the generation of atomic-squeezed states

We investigate the influence of periodically time-modulated cavity frequency on the generation of atomic squeezed states for a collection of N two-level atoms confined in a non-stationary cavity with a moving mirror. We show that the two-photon character of the field generated from the vacuum state of field plays a significant role in producing the atomic or spin squeezed states. We further show that the maximum amount of persistent atomic squeezing is obtained for the initial cavity field prepared in the vacuum state.

cond-mat.quant-gas↗
arXiv2014

Non-Equilibrium Quantum Phases of Two-Atom Dicke Model

In this paper, we investigate the non-equilibrium quantum phases of the two-atom Dicke model, which can be realized in a two species Bose-Einstein condensate interacting with a single light mode in an optical cavity. Apart from the usual non-equilibrium normal and inverted phases, a non-equilibrium mixed phase is possible which is a combination of normal and inverted phase. A new kind of quantum phase transition is predicted from non-superradiant mixed phase to the superradiant phase which can be achieved by tuning the two different atom-photon couplings. We also show that a quantum phase transition from the non-superradiant mixed phase to the superradiant phase is forbidden for certain values of the two atom-photon coupling strengths.

quant-ph↗
arXiv2014

Damping in two component Bose gas

We investigate the Landau and Baliaev damping of the collective modes in a two-component Bose gas using the mean-field approximation. We show that due to the two body atom-atom interaction, oscillations of each component is coupled to the thermal excitations of the other component which gives rise to creation or destruction of the elementary excitations that can take place in the two separate components.In addition we find that the damping is also enhanced due to inter-component coupling.

cond-mat.quant-gas↗