arXiv subjects

Avra Banerjee

Publications and source records attributed to Avra Banerjee.

6 recordsLinked to original sources

arXiv2026

Roton Instability in Quantum Droplets with Finite-Range Soft-Core Interaction

We investigate the emergence of roton instability in self-bound quantum droplets interacting via a finite-range soft-core potential modeled by a Heaviside step interaction. The ground-state properties are obtained by solving the extended Gross-Pitaevskii equation including Lee-Huang-Yang corrections with a nonlocal interaction term. The collective excitation spectrum reveals the formation and progressive softening of a roton minimum as the interaction strength and range increase. When the roton energy approaches zero, the system becomes unstable, signaling the onset of density modulation. The rotonic behavior is further characterized through the static structure factor, which exhibits pronounced peaks at the roton momentum.

cond-mat.quant-gas↗

arXiv2025

Collective excitation of Bose-Einstein condensate of Bose atoms with P\"oschl-Teller interaction

We investigate the collective excitations of Bose atoms in the condensate phase with finite-range interactions, modeled using the P\"oschl-Teller (PT) potential to explicitly account for the finite interaction range. Utilizing Bogoliubov theory, we derive the excitation spectrum and examine its dependence on interaction parameters. Our analysis reveals that the emergence and disappearance of the roton minima are directly influenced by the range of the PT interaction. Furthermore, we calculate the static structure factor and find enhanced correlations in the low-momentum regime, with their nature controlled by the characteristics of the PT potential. We have examined the interaction dependence of sound velocity and compressibility in detail.

physics.atom-ph↗

arXiv2025

Surface excitation of Rydberg dressed quantum droplet of Bose-Einstein Condensates

We have considered a quantum droplet of two components of Bose-Einstein condensate (BEC) inside the electron of a Rydberg atom to study the surface mode of collective excitation using the Bogoliubov theory of excitation. We have calculated the surface excitation spectrum for various Rydberg electron-atom interaction strengths. From the energy spectrum, we calculated the surface tension of the droplet as a function of Rydberg electron-atom interaction strength. Our study shows that the electron-atom interaction enhances the surface energy; hence, the droplet will be more stable inside the electron of a Rydberg atom.

physics.atom-ph↗

arXiv2025

Collective Excitation of Quantum Droplet with Different Ranges of the Interaction of P\"oschl-Teller Potential

In this article, we studied quantum droplet with the P\"oschl-Teller (PT) interaction potential between the Bose atoms. The Gross-Pitaevskii (GP) equation governs the system. The range and strength of the PT interaction can be adjusted. First, we studied the quantum droplet's density variation for various PT interaction parameters by the imaginary-time split-step Crank-Nicolson (CN) method. We then used the Bogoliubov theory to examine the collective excitation spectra. We observed that sharp roton forms and phonon modes are missing during long-range interactions. There is a gap at the zero momentum zone due to the long-range PT interaction, which increases with the range and strength of the interaction.

physics.atom-ph↗

arXiv2025

Low-dimensional Bose-Bose Mixture in Random Speckle Potential

In this work, we have studied the effect of the repulsive speckle potential in a mixture of Bose-Einstein condensates in one dimension (1D) and two dimension (2D). We simulated linear and circular random speckle potentials in 1D and 2D, respectively. Our calculation shows that the condensate density forms a sharp ring in 2D, and the condensate is divided into two parts in 1D at a high impurity density of speckle potential. We have calculated the energy and chemical potential of the system by solving the Gross-Pitaevskii (GP) equation to see the stability of the condensate. In our study, we have seen that the nature of the impurity response is the same for one-dimensional and two-dimensional quantum droplets.

cond-mat.quant-gas↗

arXiv2023

Collective excitations of Bose-Einstein Condensate in a Rydberg Atom

In this work, we investigated a Bose-Einstein condensate (BEC) inside a Rydberg atom. We first observed the density profile of the system using the Gross-Pitaevskii equation, and then we used the Bogoliubov theory to examine the collective excitation spectra. We have also extended our study by taking into account a hybrid of two BEC species. Again, for this new system, the density profile and the collective excitation are investigated in a similar manner. The results of the BEC for one species reveal that the Rydberg atom can trap the BEC and that the excitation curve moves upward with increasing Rydberg atom interaction. We have seen roton minima for two species of BEC, and the depth of the minima shifts with the Rydberg interaction.

physics.atom-ph↗