Spatial non-locality in confined quantum systems: a liaison with quantum correlations

TL;DR

This paper investigates the relationship between spatial non-locality and quantum correlations in confined bosonic systems using stochastic quantum Monte Carlo methods, revealing that non-locality closely relates to spatial uncertainty and quantum correlations.

Contribution

It demonstrates that the nonlocal correlation length in TDQMC is nearly equal to the spatial uncertainty and is largely independent of particle number in 2D systems, linking non-locality with quantum correlations.

Findings

Nonlocal correlation length approximates the standard deviation of the Monte Carlo sample.

Spatial non-locality is nearly independent of the number of bosons in 2D systems.

Spatial non-locality is closely connected to quantum correlations.

Abstract

Using advanced stochastic methods (time-dependent quantum Monte Carlo, TDQMC) we explore the ground state of 1D and 2D artificial atoms with up to six bosons in harmonic trap where these interact by long-range and short-range Coulomb-like potentials (bosonic quantum dots). It is shown that the optimized value of the key variational parameter in TDQMC named nonlocal correlation length is close to the standard deviation of the Monte Carlo sample for one boson and it is slightly dependent on the range of the interaction potential. Also it is almost independent on the number of bosons for the 2D system thus confirming that the spatial quantum non-locality experienced by each particle is close to the spatial uncertainty exhibited by the rest of the particles. The intimate connection between spatial non-locality and quantum correlations is clearly evidenced.