Regular Article

Exceptional Points from the Hamiltonian of a hybrid physical system: Squeezing and anti-Squeezing^★

¹ Department of Mathematics, National University of La Plata, La Plata, Argentina
² IFLP, CONICET-Department of Physics, National University of La Plata, La Plata, Argentina
³ IFLP, CONICET-Faculty of Engineering, National University of La Plata, La Plata, Argentina

^a Corresponding author: reboiro@fisica.unlp.edu.ar

Received: 15 April 2020
Accepted: 3 August 2020 Received in final form: 3 July 2020

Published online: 22 September 2020

Abstract

We study the appearance of Exceptional Points in a hybrid system composed of a superconducting flux-qubit and an ensemble of nitrogen-vacancy colour centres in diamond. We discuss the possibility of controlling the generation of Exceptional Points, by the analysis of the model space parameters. One of the characteristic features of the presence of Exceptional Points, is the departure from the exponential decay behaviour of the observables as a function of time. We study the time evolution of different initial states, in the presence of the hybrid system, by computing the reduced density matrix of each subsystem. We present the results we have obtained for the steady behaviour of different observables. We analyse the appearance of Squeezed Spin States and anti-Squeezed Spin States.