On demand entanglement in double quantum dots via coherent carrier scattering

Abstract

We show how two qubits encoded in the orbital states of two quantum dots can be entangled or disentangled in a controlled way through their interaction with a weak electron current. The transmission/reflection spectrum of each scattered electron, acting as an entanglement mediator between the dots, shows a signature of the dot-dot entangled state. Strikingly, while a few scattered carriers produce decoherence of the whole two-dot system, a larger number of electrons injected from one lead with proper energy are able to recover its quantum coherence. Our numerical simulations are based on a real-space solution of the three-particle Schrödinger equation with open boundaries. The computed transmission amplitudes are inserted in the analytical expression for the system density matrix to evaluate the entanglement. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.