Realizable spin models and entanglement dynamics in superconducting flux qubit systems

TL;DR

This paper demonstrates how to engineer artificial two-spin systems using superconducting flux qubits by tuning parameters, enabling the study of entanglement dynamics through time evolution of quantum states.

Contribution

It introduces a method to realize artificial two-spin models in superconducting flux qubits and analyzes their entanglement dynamics, which are not naturally occurring.

Findings

Artificial two-spin systems can be realized by parameter tuning.

Unentangled states can evolve into maximally entangled states periodically.

Entanglement dynamics are characterized by concurrence and fidelity over time.

Abstract

Realizable spin models are investigated in a two superconducting flux qubit system. It is shown that a specific adjustment of system parameters in the two flux qubit system makes it possible to realize an artificial two-spin system that cannot be found naturally. For the artificial two-spin systems, time evolution of a prepared quantum state is discussed to quantify quantum entanglement dynamics. The concurrence and fidelity as a function of time are shown to reveal a characteristic entanglement dynamics of the artificial spin systems. It is found that the unentangled input state can evolute to be a maximally entangled output state periodically due to the exchange interactions induced by two-qubit flipping tunneling processes while single-qubit flipping tunneling processes plays a role of magnetic fields for the artificial spins.