Steady-State Tunable Entanglement Switch with Quantum Dots

Abstract

^*We present a nanoscale device capable of non-deterministically producing maximal entanglement between two distant uncoupled ancilla qubits. A single quantum dot device with anti-parallel spin polarized leads coupled to two impurity spin qubits is shown to generate steady state entanglement between the two qubits. Steady states are obtained via application of Liouvillian superoperator theory for the entire dot-impurity system. The steady state entanglement between ancillary qubits is tunable and can be controlled by the applied voltage and other parameters. In the end, we provide a postselection scheme to generate maximal entanglement states out of the non-maximally entangled steady states of the system.