We study the potential for controlled transfer of population to the biexciton state of a semiconductor quantum dot coupled with a metal nanoparticle, under the influence of an electromagnetic pulse with hyperbolic secant shape, and derive analytical solutions of the density matrix equations for both zero and nonzero biexciton energy shifts. These solutions lead to efficient transfer to the biexciton state for various interparticle distances including relatively small values. In certain cases, when the distance between the two particles is small, the transfer of population is strongly modified because of the influence of surface plasmons to the excitons, and the effect is more pronounced for shorter pulses. The hybrid nanostructure that we study has been proposed for generating efficient polarization-entangled photons, and thus, the successful biexciton state preparation considered here is expected to contribute in this line of research.

中文翻译：

---

与金属纳米粒子耦合的半导体量子点中双激子态的相干制备

我们研究了在具有双曲割线形状的电磁脉冲的影响下，人口受控转移到与金属纳米粒子耦合的半导体量子点的双激子态的潜力，并推导出零和非零密度矩阵方程的解析解双激子能量转移。这些解决方案导致对于各种粒子间距离（包括相对较小的值）有效地转移到双激子状态。在某些情况下，当两个粒子之间的距离很小时，由于表面等离子体激元对激子的影响，粒子群的转移会发生强烈的改变，而且对于较短的脉冲，这种影响更为明显。我们研究的混合纳米结构已被提议用于产生有效的偏振纠缠光子，因此，