Collapse and revival of entanglement of two-qubit in superconducting quantum dot lattice with magnetic flux and inhomogeneous gate voltage

TL;DR

This paper investigates how magnetic flux and gate voltage inhomogeneity affect entanglement in a two-qubit superconducting quantum dot lattice, revealing universal entanglement suppression at half-integer flux quanta and conditions for maximal entanglement.

Contribution

It provides new insights into the effects of magnetic flux and gate voltage inhomogeneity on entanglement dynamics in superconducting quantum dot lattices.

Findings

Entanglement is washed out at half-integer magnetic flux quanta.

Ground state is maximally entangled without gate voltage inhomogeneity.

Finite temperature behavior of entanglement differs from zero temperature.

Abstract

We study the entanglement of a two-qubit system in a superconducting quantum dot (SQD) lattice in the presence of magnetic flux and gate voltage inhomogeneity. We observe a universal feature for the half-integer magnetic flux quantum which completely washes out the entanglement of the system both at zero and finite temperature. We observe that the ground state is always in a maximally entangled Bell state when there is no inhomogeneity in gate voltage in the superconducting quantum dot lattice. We find an important constraint in magnetic flux for ground state entanglement. We also observe few behavior of entanglement at finite temperature is in contrast with the zero temperature behavior.