Entanglement, Dephasing, and Phase Recovery via Cross-Correlation Measurements of Electrons

Abstract

Determination of the path taken by a quantum particle leads to a suppression of interference and to a classical behavior. We employ here a quantum 'which path' detector to perform accurate path determination in a two-path-electron-interferometer; leading to full suppression of the interference. Following the dephasing process we recover the interference by measuring the cross-correlation between the interferometer and detector currents. Under our measurement conditions every interfering electron is dephased by approximately a single electron in the detector - leading to mutual entanglement of approximately single pairs of electrons.