Mott transition, biexciton crossover, and spin ordering in the exciton gas in quantum wells
Mott transition, biexciton crossover, and spin ordering in the exciton gas in quantum wells
复制标题
量子阱中激子气体的莫特跃迁、双激子交叉和自旋排序
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
B. Laikhtman
中科院分区：
文献类型：
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作者：
S. de;B. Laikhtman
给出了单量子阱和耦合量子威尔斯中激子气体的相图。在后一种情况下，电子和空穴在空间上分离。在单阱和耦合量子威尔斯阱中，都存在从激子气体到电子空穴等离子体的Mott跃迁。在温度低于莫特转变在一个单一的量子阱，有一个交叉的双激子气相。双激子气体的形成排除了激子的Kosterlitz-Escherless跃迁。在耦合量子威尔斯阱中，激子间的强直接排斥作用阻碍了双激子的形成。如果电子和空穴之间的距离足够大，温度的降低导致转变到具有自发自旋极化的铁磁激子相。温度的进一步降低导致激子气体的Kosterlitz-nickelless转变。我们讨论了可能的实验，可以区分不同阶段的激子气体。
We present the phase diagram of exciton gas in single and coupled quantum wells. In the latter case, electrons and holes are spatially separated. In both single and coupled quantum wells there is a Mott transition from the exciton gas to electron-hole plasma. In temperatures below the Mott transition in a single quantum well, there is a crossover to a biexciton gas phase. The formation of biexciton gas rules out the Kosterlitz-Thouless transition of excitons. In coupled quantum wells, the strong direct repulsion between excitons prevents the biexciton formation. If the separation between the electrons and holes is large enough, the decrease of temperature leads to the transition to a ferromagnetic exciton phase with a spontaneous spin polarization. Further decrease of the temperature leads to the Kosterlitz-Thouless transition of the exciton gas. We discuss possible experiments that can distinguish different phases of the exciton gas.