Quantum entanglement of electrons in a biased 1D two-probe device

TL;DR

This paper investigates how electronic quantum entanglement in a 1D two-probe device is affected by voltage bias, revealing entropy reduction, jumps at energy alignments, and symmetry effects using nonequilibrium Green's functions.

Contribution

It extends entanglement entropy analysis to nonequilibrium conditions in a 1D device, highlighting bias-dependent behavior and symmetry effects.

Findings

Entanglement entropy decreases with applied bias.

Entropy exhibits jumps when energy levels align.

Odd-even symmetry effects influence entanglement behavior.

Abstract

Electronic quantum entanglement between the central chain and the two electrodes in an infinite one-dimensional two-probe device system is studied. The entanglement entropy is calculated employing the nonequilibrium Green's function method in the tight-binding model based on the relation between the correlation matrix and the von Neumann entropy. By extending the entropy to nonequilibrium cases, we have studied the scaling behavior when a voltage bias is applied between the two electrodes. The entropy usually decreases with the bias and may jump up when a quasi-state in the chain aligns in energy with the band edges in the electrodes. Odd-even effect is observed due to the symmetry of the chain.