arXiv subjects

Kajal Krishna Dey

Publications and source records attributed to Kajal Krishna Dey.

4 recordsLinked to original sources

arXiv2026

Simulation of single-qubit gates in spin-orbit coupled Bose-Einstein condensate with cubic-quintic nonlinearity by nonlinear perturbations

We consider spin-orbit coupled Bose-Einstein condensates with cubic-quintic nonlinear interaction within the framework of second quantization formulation and find eigen states using numerical simulation and mean-field approximation. We show that two low-lying Schrodinger cat states remain degenerate up to a certain value of Raman coupling strength and these states can serve as qubit basis. We take three different nonlinear perturbations and find that the perturbations can result in different rotations of qubit state on Bloch sphere. We calculate the unitary operator corresponding to each perturbation and suggest the possibilities for obtaining various gates in ultra-cold atomic system.

cond-mat.quant-gas↗

arXiv2024

Effective spin dynamics of spin-orbit coupled matter-wave solitons in optical lattices

We consider matter-wave solitons in spin-orbit coupled Bose-Einstein condensates embedded in optical lattice and study dynamics of soliton within the framework of Gross-Pitaevskii equations. We express spin components of the soliton pair in terms of nonlinear Bloch equation and investigate effective spin dynamics. It is seen that the effective magnetic field that appears in the Bloch equation is affected by the optical lattices, and thus the optical lattice influences the precessional frequency of the spin components. We make use of numerical approaches to investigate the dynamical behavior of density profiles and center-of-mass of the soliton pair in presence of the optical lattice. It is shown that the spin density is periodically varying due to flipping of spinors between the two states. The amplitude of spin flipping oscillation increases with lattice strength. We find that the system can also exhibit interesting nonlinear behavior for chosen values of parameters. We present a fixed point analysis to study the effects of optical lattices on the nonlinear dynamics of the spin components. It is seen that the optical lattice can act as a control parameter to change the dynamical behavior of the spin components from periodic to chaotic.

cond-mat.quant-gas↗

arXiv2021

Optical solitons in saturable cubic-quintic nonlinear media with nonlinear dispersion

We study an intense-short pulse propagation in a saturable cubic-quintic nonlinear media in the presence of nonlinear dispersion within the framework of an extended variational approach. We derive an effective equation for the pulse width and demonstrate how the saturation due to nonlinearity is achieved in presence of nonlinear dispersion. We find that the nonlinear dispersion can change the pulse width and induce motion in the system. The direction of induced motion depends on the sign of nonlinear dispersion. The pulse is energetically stable at an equilibrium width. A disturbance can, however, induce oscillation in pulse width, the frequency of which is always smaller due to nonlinear dispersion. We check dynamical stability by a direct numerical simulation.

physics.atom-ph↗

arXiv2018

On the information entropy of matter-waves in quasi-disorder potentials

We consider ultracold Bose gases in quasi-random potentials and quantify localization of matter waves by means of Shannon information entropy. We explicitly examine the role of quasi-random potentials in producing localized states in the linear and nonlinear regimes. It is seen that the information entropic-based approach can be more useful to quantify localization of different types of states observed in Bose-Einstein condensates.

cond-mat.quant-gas↗