Efficient protocol for qubit initialization with a tunable environment

Abstract

Quantum computers: Back to square zero The ability to accurately reset qubits is one of the fundamental criteria in implementing quantum computers. Jani Tuorila and co-workers from Aalto University (Finland) propose a qubit initialization protocol using a dynamically adjustable environment. The scheme differs from the conventional methods which reach for a given qubit state with microwave cooling or projective measurements of the qubit. The protocol relies on enhancing the dissipation to the qubit ground state by tuning an engineered environment on resonance with the qubit. The new theoretical study suggests that the experimental benchmark for the initialization speed at a given precision can be increased with this method almost by an order of magnitude. Such an improvement would present a significant step towards meeting the stringent operational conditions of a working largescale quantum computer.