Jho Y D, Wang Xiaoming, Kono J, Reitze D H, Wei X, Belyanin A A, Kocharovsky V V, Kocharovsky Vl V, Solomon G S
Department of Physics, University of Florida, Gainesville, Florida 32611, USA.
Phys Rev Lett. 2006 Jun 16;96(23):237401. doi: 10.1103/PhysRevLett.96.237401. Epub 2006 Jun 12.
We investigate photoluminescence from a high-density electron-hole plasma in semiconductor quantum wells created via intense femtosecond excitation in a strong perpendicular magnetic field, a fully quantized and tunable system. At a critical magnetic field strength and excitation fluence, we observe a clear transition in the band-edge photoluminescence from omnidirectional output to a randomly directed but highly collimated beam. In addition, changes in the linewidth, carrier density, and magnetic field scaling of the photoluminescence spectral features correlate precisely with the onset of random directionality, indicative of cooperative recombination from a high-density population of free carriers in a semiconductor environment.
我们研究了在强垂直磁场中通过强飞秒激发产生的半导体量子阱中高密度电子 - 空穴等离子体的光致发光，这是一个完全量子化且可调谐的系统。在临界磁场强度和激发通量下，我们观察到带边光致发光从全向输出到随机定向但高度准直光束的明显转变。此外，光致发光光谱特征的线宽、载流子密度和磁场标度的变化与随机方向性的出现精确相关，这表明在半导体环境中自由载流子的高密度群体发生了协同复合。
