Dynamical generation and detection of entanglement in neutral leviton pairs

TL;DR

This paper demonstrates that current cross-correlation measurements in an electronic Mach-Zehnder interferometer can effectively detect entanglement between electron-hole pairs, even under realistic experimental conditions.

Contribution

It introduces a method to detect electron-hole entanglement via current correlations, overcoming previous limitations due to particle number conservation.

Findings

Robust witness of electron-hole entanglement using current cross-correlations.

Entangled neutral excitations generated by periodic modulation of a quantum point contact.

Analysis of finite temperature and dephasing effects on entanglement detection.

Abstract

The entanglement of coherently split electron-hole pairs in an electronic conductor is typically not considered accessible due to particle number conservation and fermionic super-selection rules. We demonstrate here that current cross-correlation measurements at the outputs of an electronic Mach-Zehnder interferometer can nevertheless provide a robust witness of electron-hole entanglement. Specifically, we consider neutral excitations generated by modulating the transmission of an unbiased quantum point contact periodically in time. For an optimized modulation profile, an entangled state with one positively-charged leviton (a hole) and one negatively-charged leviton (an electron) gets delocalized over the two paths of the interferometer and is detected at the output arms. We evaluate the influence of finite electronic temperatures and dephasing corresponding to recent experiments.