Rapid biexciton state preparation in a quantum dot using on-off pulse-sequences

TL;DR

This paper introduces a rapid pulse-sequence method for efficient biexciton state preparation in quantum dots, outperforming traditional pulses in speed and robustness against dissipation.

Contribution

It proposes a simple on-off-on pulse-sequence optimized for fast and high-fidelity biexciton preparation, validated through numerical optimal control and simulations.

Findings

Pulse-sequence achieves faster biexciton preparation than traditional methods.

Numerical optimization finds minimal time pulses for various amplitudes.

High fidelity is maintained even with dissipation and dephasing.

Abstract

We consider the problem of pulsed biexciton preparation in a quantum dot and show that a pulse-sequence with a simple on-off-on modulation can achieve complete preparation of the target state faster than the commonly used constant and hyperbolic secant pulses. The durations of the pulses composing the sequence are obtained from the solution of a transcendental equation. Furthermore, using numerical optimal control, we demonstrate that for a wide range of values of the maximum pulse amplitude, the proposed pulse-sequence prepares the biexciton state in the numerically obtained minimum time, for the specific system under consideration. We finally show with numerical simulations that, even in the presence of dissipation and dephasing, high levels of biexciton state fidelity can be generated in short times.