Control and manipulation of entanglement between two coupled qubits by fast pulses

TL;DR

This paper explores how fast external pulses can be used to control and sustain entanglement between two coupled qubits, highlighting the importance of pulse design and timing in quantum information processing.

Contribution

It provides analytical and numerical insights into manipulating entanglement with tailored fast pulses in a Heisenberg XXX interaction model.

Findings

Fast pulses can generate long-lasting entanglement.

Pulse strength and direction significantly affect entanglement dynamics.

Time ordering effects are crucial in entanglement control.

Abstract

We have investigated the analytical and numerical dynamics of entanglement for two qubits that interact with each other via Heisenberg XXX-type interaction and subject to local time-specific external kick and Gaussian pulse-type magnetic fields in x-y plane. The qubits have been assumed to be initially prepared in different pure separable and maximally entangled states and the effect of the strength and the direction of external fast pulses on concurrence has been investigated. The carefully designed kick or pulse sequences are found to enable one to obtain constant long-lasting entanglement with desired magnitude. Moreover, the time ordering effects are found to be important in the creation and manipulation of entanglement by external fields.