Coherent Excitonic Wavepackets in Two-Dimensional Square Dot-Arrays Driven by an In-Plane Uniform Electric Field

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2004,（1）
• 页码范围: 197-200
• 页数: 4页
• 语种: 英文

摘要

We investigate the evolution behaviour of electron-hole pair wavepacket in optically excited square quantum-dot arrays driven by in-plane (x-y plane) uniform electric field E (viz, E ＝ Exex + Eyey, ex,ey are unit vectors along x and y directions respectively), in the time domain. It is found that if the ratio of the x-component electric field Ex to the y-component electric field Ey is a rational p/q (p and q being coprime integer numbers),the wavepackets undergo a time-periodic breathing mode, with the period 2πp/ωBx, where ωBx ＝ eExa/h, with a being the lattice constant of square dot arrays, h being Planck's constant, e being the electron charge. This finding provides a time-domain demonstration of the recent spectral result [Phys. Rev. Lett. 86 (2001)3116].