Effects of spatial nonlocality versus nonlocal causality for bound electrons in external fields

TL;DR

This paper compares the effects of spatial nonlocality and nonlocal causality on entangled electrons in external fields using exact quantum simulations, highlighting the predictive accuracy of spatial nonlocality for entanglement.

Contribution

It demonstrates that spatial nonlocality effectively predicts entanglement measures, while nonlocal causality causes minimal trajectory oscillations in a two-electron system.

Findings

Spatial nonlocality accurately predicts quantum entanglement.

Nonlocal causality causes small oscillations in quantum trajectories.

The approach uses numerically exact solutions and quantum Monte Carlo methods.

Abstract

Using numerically exact solution of the time-dependent Schroedinger equation together with time-dependent quantum Monte Carlo (TDQMC) calculations we compare the effects of spatial nonlocality versus nonlocal causality for the ground state and for real-time evolution of two entangled electrons in parabolic potential in one spatial dimension. It was found that the spatial entanglement quantified by the linear quantum entropy is predicted with good accuracy using the spatial nonlocality, parameterized naturally within the TDQMC approach. At the same time, the nonlocal causality predicted by the exact solution leads to only small oscillations in the quantum trajectories which belong to the idler electron as the driven electron is subjected to a strong high frequency electric field, without interaction between the electrons.