We consider the problem of pulsed biexciton preparation in a quantum dot, and we 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.

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使用开关脉冲序列在量子点中快速完成双激子态制备

我们考虑了量子点中脉冲双激子准备的问题，并且我们证明了具有简单开-关-开调制的脉冲序列可以比常用的恒定和双曲线割线脉冲更快地完成目标状态的准备。构成序列的脉冲的持续时间从先验方程的解中获得。此外，使用数值最优控制，我们证明了对于最大脉冲幅度的宽范围值，所提出的脉冲序列在考虑的特定系统的数值获得的最短时间内准备了双激子态。我们最终通过数值模拟表明，即使存在耗散和相移的情况，也可以在短时间内生成高水平的双激子态保真度。