arXiv subjects

Avinaba Mukherjee

Publications and source records attributed to Avinaba Mukherjee.

4 recordsLinked to original sources

arXiv2026

Coherence Resonance Phenomena in an Atom-Dimer Two Mode BECs

We investigate the non-equilibrium dynamics of atomic-molecular Bose-Einstein condensates coupled via a Feshbach resonance, with Gaussian white noise acting on both the coupling strength and the detuning. Using the bosonic Josephson-junction and Bloch-sphere formalisms, we examine how coherence (coupling) noise and imbalance (detuning) noise modify the coherence-resonance point as functions of the initial polarization and the Feshbach detuning. Noise plays a more coherent role when its characteristic timescale matches the intrinsic timescales of the dynamics, leading to extrema in the time-averaged purity and the Husimi-Q distribution.

cond-mat.quant-gas↗

arXiv2026

Fluctuation Spectra and Response Function of Coupled Atomic and Molecular BECs

We investigate out-of-equilibrium properties of atomic molecular Bose Einstein condensates coupled through a Feshbach resonance, with the Feshbach coupling and detuning subject to Gaussian white noise. Using a bosonic Josephson junction framework and a Bloch sphere description, we examine the interplay of detuning, coherence, and noise governing the system dynamics. Coupling and detuning noise produce distinct fluctuation spectra, featuring both Feshbach resonant and symmetric off resonant peaks. We characterize the dispersive and absorptive response of the atom dimer system under periodic driving. The atom molecule hybridization at the Feshbach resonance maximizes the linewidth and minimizes both the effective temperature and the phase difference between the driving field and the system. This leads to an optimized power utilization and quality factor.

cond-mat.quant-gas↗

arXiv2025

Roles of Polarization and Detuning in the Noise-induced Relaxation Dynamics of Atomic-Molecular Bose Condensates

We study the relaxation process of a resonant Bose gas under the influence of Gaussian white noise. We characterize the system dynamics in terms of the polarization or imbalance between the atoms and molecules, and the system coherence. The relaxation times corresponding to these two quantities are studied both using a mean-field model, and a Born Green Kirkwood Yvon hierarchy that takes into account the higher-order correlations. The role of the initial polarization and the Feshbach detuning are investigated. It is found with an increasing initial population imbalance, the longituidinal relaxation time (that governs the dyanamics of the polarization) grows, while the transverse relaxation time (that governs the dynamics of the coherence) decays. As for the varying Feshbach detuning, it is observed that the longituidinal relaxation time reaches its minima and its transverse counterpart reaches its maxima near the resonance. We also study how the initial polarization and the detuning affect physical quantities like drift speed, condensate fraction, fidelity and entanglement entropy etc, and find the results to be fully consistent with the behavior of the relaxation dynamics of the system.

cond-mat.quant-gas↗

arXiv2024

Periodic dynamics of population-imbalanced fermionic condensates in optical lattices

We investigate the dynamics of a population-imbalanced two-species fermionic system trapped in an optical lattice. The paired fermions here can form bosonic molecules via Feshbach coupling in the presence of an external magnetic field. It is shown that the natural fluctuations of the condensate fraction are periodic beyond a threshold Feshbach detuning; and below this threshold value, the condensate fraction shows no oscillation at all. The oscillation frequency vs. detuning curve is linear in nature. The slope and intercept of this line are shown to carry important information about the amount of imbalance present in the system, and the momentum space structure of the exotic phases.

cond-mat.quant-gas↗