2022/05/25 by Md Hamid, Hamid, Md, M. A. H. Ahsan +1 · 1 citation
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #Quantum Gases (cond-mat.quant-gas) #Quantum, superfluid, helium dynamics #Spectroscopy and Quantum Chemical Studies
paper · pdf · doi:10.48550/arxiv.2205.12614
openalex publication_date 2022/05/25 · openalex created_date 2022/06/13 · openalex updated_date 2026/07/28
We present exact diagonalization study on a system of 10 ≤ N ≤ 24 spinless bosons interacting via repulsive Gaussian potential, harmonically confined in xy-plane with an externally impressed rotation about the z-axis. The two-body interaction strength in the Gaussian potential is taken in the strongly interacting regime with values of interaction range in the regime 0≤ σ≤ 1. The diagonalization of the N-body Hamiltonian matrix, in subspaces of total angular momentum in the regime 0≤ Lz ≤ 4N corresponds to the filling fraction ν\lesssim 3.2 is carried out to obtain the variationally exact ground-state wavefunction and the corresponding eigenvalue. It is found that an increase in interaction range σ leads to (a) a systematic decrease in energy, (b) an increase in the critical angular velocity Ω_ci of the ith vortex state and (c) an increase in the largest eigenvalue λ1, (condensate fraction), of one-particle reduced density matrix (OPRDM). The von Neumann entropy S1(Lz,σ), quantifying the quantum entanglement between the particles in the many-body ground state, is largely found to decrease with increase in σ. Crossings in von Neumann entropy for several of the angular momentum states are observed with variation in σ. The response of the Bose-Einstein condensate to rotation is examined through Lz(σ)-Ω(σ) stability graph for several values of σ. A vortex state with larger plateau length on the Lz-Ω graph is considered to be more stable. The internal structure of the condensate, as depicted by the conditional probability distribution (CPD) in the body-fixed frame, exhibits characteristic features with interaction range σ. One such feature is the merging of the cores of the two-vortex state.