Regular Article

Thermal preparation of an entangled steady state of distant nitrogen-vacancy-center ensembles

Ulyanovsk State Pedagogical University, Ulyanovsk 432071, Russia

^a e-mail: teper@rambler.ru

Received: 18 May 2020
Received in final form: 5 August 2020
Accepted: 20 August 2020
Published online: 5 October 2020

Abstract

Steady state entanglement is studied in the continuous-variable system of two distant nitrogen-vacancy-center ensembles (NVEs) driven by squeezed microwave field. Transmission line resonators and a current-biased Josephson junction are used for transfer of excitations between two NVEs. The circuit is enhanced by Josephson parametric amplifiers (JPAs), which produce squeezed microwave field. Squeezed fields of JPAs are driving force, which provides generation of an entangled steady state of two bosonic modes of NVEs for a wide range of system parameters.