Quantum Statistics and Kinetics of Excitons

半导体晶体在低温下的光激发产生可移动的电子和空穴，它们结合形成短寿命的激子。由于它们的轻质量，激子是一种被称为玻色-爱因斯坦凝聚（BEC）的新型量子效应的候选者。在低温强脉冲激光激发下，高纯CU2O单晶中的激子表现出量子统计特性，导致BEC。目前的研究将创建和探索这个不寻常的系统，以检查弛豫动力学，并试图产生BEC。通过对晶体施加应力和磁场来优化观察条件。应变约束和亚开尔文温度将用于产生长寿命的量子激子气体，并允许在宏观距离上观察激子的弹道传播。

Optical excitation of a semiconductor crystal at low temperature produces mobile electrons and holes which combine to form short lived excitons. Because of their light mass, excitons are candidates for a novel quantum effect called Bose-Einstein Condensation (BEC). Under intense pulsed laser excitation at low temperature, excitons in high-purity single crystals of CU2O display properties characteristic of quantum statistics leading to BEC. The present studies will create and probe this unusual system to examine the relaxation kinetics and to attempt to produce BEC. To conditions for observation will be optimized by applying stress and magnetic fields to the crystal. Strain-confinement and sub-Kelvin temperature will be used to produce long-lived quantum exciton gas and allow the possibility of observing ballistic propagation of excitons over macroscopic distances.