Investigation of Confinement Induced Resonance in Atomic Waveguides with Different Geometries by Quantum Monte Carlo Methods

TL;DR

This study uses quantum Monte Carlo methods to explore confinement induced resonance in ultracold bosons within different waveguide geometries, revealing geometry-dependent resonance behavior and phase transitions to fermion-like states.

Contribution

It demonstrates the occurrence of confinement induced resonance in toroidal waveguides and shows that the resonance position varies with waveguide size, unlike in cigar-shaped geometries.

Findings

CIR occurs in both cigar-shaped and toroidal waveguides.

Resonance position depends on waveguide size in toroidal geometries.

System transitions to a fermion-like TG gas in the CIR regime.

Abstract

We have investigated the quantum dynamics of two ultracold bosons inside an atomic waveguide for two different confinement geometries (cigar-shaped and toroidal waveguides) by quantum Monte Carlo methods. For quasi-1D gases, the confining potential of the waveguide leads to the so-called confinement induced resonance (CIR), results in the phase transition of the gas to the impenetrable bosonic regime (known as TG gas). In this regime the bosons repel each other strongly and behave like fermions. We reproduce CIR for a cigar-shaped waveguide and analyze the behavior of the system for different conditions. Moreover, our analysis demonstrates appearance of CIR for a toroidal waveguide. Particularly, we show that the resonance position is dependent on the size of the waveguide, which is in contrast to the cigar shaped waveguides for which it is universal.