arXiv subjects

F. Saif

Publications and source records attributed to F. Saif.

7 recordsLinked to original sources

arXiv2022

PT-Symmetric potential impact on the scattering of a Bose-Einstein condensate from a Gaussian Obstacle

The scattering of a Bose-Einstein Condensate (BEC) from a Gaussian well and Gaussian barrier is investigated over a wide range of depths and heights, respectively. We compare analytical and numerical results for a BEC scattering from Gaussian Obstacles, both in the presence and in the absence of PT-symmetric potential. And we find out that the Complex Ginzburg-Landau Equation (CGLE) method has limitations due to the limited number of variational parameters of the ansatz. We also find that the presence of the PT-symmetric potential controls the reflection and the transmission flux of the BEC through the Gaussian Obstacle.

quant-ph↗

arXiv2018

Loss-induced transparency in optomechanics

We study optomechanically induced transparency (OMIT) in a compound system consisting of coupled optical resonators and a mechanical mode, focusing on the unconventional role of loss. We find that optical transparency can emerge at the otherwise strongly absorptive regime in the OMIT spectrum, by using an external nanotip to enhance the optical loss. In particular, loss-induced revival of optical transparency and the associated slow-to-fast light switch can be identified in the vicinity of an exceptional point. These results open up a counterintuitive way to engineer micro-mechanical devices with tunable losses for e.g., coherent optical switch and communications.

quant-ph↗

arXiv2016

Engineering single-phonon number states of a mechanical oscillator via photon subtraction

We introduce an optomechanical scheme for the probabilistic preparation of single-phonon Fock states of mechanical modes based on photo-subtraction. The quality of the produced mechanical state is confirmed by a number of indicators, including phonon statistics and conditional fidelity. We assess the detrimental effect of parameters such as the temperature of the mechanical system and address the feasibility of the scheme with state-of-the-art technology.

quant-ph↗

arXiv2015

Single Phonon State of Mechanical Mode via Photon Subtraction

We prepare single phonon Fock state of mechanical mode in optomechanical system based on photon subtraction process in the linear regime of optomechanical interaction. The correlation set between cavity and field modes is utilized to recast the state of a pre-cooled mechanical mode into a single phonon Fock state as the field mode is subjected to a photon subtraction type measurement at a dynamical instant of interaction time. The resultant conditional state of mechanical mode quantified by its Wigner function, exhibits an excellent compatibility with the standard single quantum Fock state. We confirm the nature of obtained state by calculating the phonon statistics, and conditional fidelity which approaches to unity for an instantaneous measurement time within an appropriate choice of parametric regime. Moreover, we also study the effects of temperature parameter for the preparation of target state. The present scheme can be realized to engineer the single quantum Fock state of macroscopic mechanical mode with currently available technology.

quant-ph↗

arXiv2008

Generation of maximally entangled states of two cavity modes

In this letter we present a scheme for generating maximally entangled states of two cavity modes which enables us to generate complete set of Bell basis states having rather simple initial state preparation. Furthermore, we study the interaction of a two-level atom with two modes of electromagnetic field in a high Q cavity. The two-level atom acts as a control qubit and the two mode electromagnetic field serves as a target qubit. This simple system of quantum electrodynamics provides us experimentally feasible universal quantum logic gates.

quant-ph↗

arXiv2000

Quantum Revivals in a Periodically Driven Gravitational Cavity

Quantum revivals are investigated for the dynamics of an atom in a driven gravitational cavity. It is demonstrated that the external driving field influences the revival time significantly. Analytical expressions are presented which are based on second order perturbation theory and semiclassical secular theory. These analytical results explain the dependence of the revival time on the characteristic parameters of the problem quantitatively in a simple way. They are in excellent agreement with numerical results.

quant-ph↗

arXiv1998

Quantum Carpets made simple

We show that the concept of degeneracy is the key idea for understanding the quantum carpet woven by a particle in the box.

quant-ph↗