Quantum optimal control of the dissipative production of a maximally entangled state

TL;DR

This paper demonstrates how quantum optimal control can enhance the speed and fidelity of entanglement generation in dissipative systems, specifically in trapped ion qubits, by optimizing experimental parameters.

Contribution

It introduces a method to improve entanglement fidelity and speed through optimal control techniques, including polarization optimization and transition selection.

Findings

Optimizing laser polarization increases entanglement fidelity.

Combining transition choices with polarization optimization speeds up entanglement.

Error rates decrease by an order of magnitude with the proposed method.

Abstract

Entanglement generation can be robust against noise in approaches that deliberately incorporate dissipation into the system dynamics. The presence of additional dissipation channels may, however, limit fidelity and speed of the process. Here we show how quantum optimal control techniques can be used to both speed up the entanglement generation and increase the fidelity in a realistic setup, whilst respecting typical experimental limitations. For the example of entangling two trapped ion qubits [Lin et al., Nature 504, 415 (2013)], we find an improved fidelity by simply optimizing the polarization of the laser beams utilized in the experiment. More significantly, an alternate combination of transitions between internal states of the ions, when combined with optimized polarization, enables faster entanglement and decreases the error by an order of magnitude.