Entanglement generation through an open quantum dot: an exact approach

TL;DR

This paper provides an exact analytical study of entanglement generation in an open quantum dot system, revealing how Coulomb interactions induce spin-singlet bound states that facilitate entanglement transfer.

Contribution

It introduces an exact approach to analyze entanglement in the Anderson model, including the derivation of two-electron scattering states with Coulomb-induced bound states.

Findings

Only spin-singlet states transmit during cotunneling.

Bound states are induced by Coulomb interaction and are not Bethe eigenstates.

The scattering process involves non-conserved momenta due to bound states.

Abstract

We analytically study entanglement generation through an open quantum dot system described by the two-lead Anderson model. We exactly obtain the transition rate between the non-entangled incident state in one lead and the outgoing spin-singlet state in the other lead. In the cotunneling process, only the spin-singlet state can transmit. To discuss such an entanglement property in the open quantum system, we construct the exact two-electron scattering state of the Anderson model. It is striking that the scattering state contains spin-singlet bound states induced by the Coulomb interaction. The bound state describes the scattering process in which the set of momenta is not conserved and hence it is not in the form of a Bethe eigenstate.