Two-dimensional semimetal in HgTe quantum well under hydrostatic pressure
Two-dimensional semimetal in HgTe quantum well under hydrostatic pressure
复制标题
DOI：
10.1103/physrevb.98.155437
复制
发表时间：
2017-12
影响因子：
3.7
通讯作者：
V. Prudkoglyad;E. Olshanetsky;Z. Kvon;V. Pudalov;N. N. Mikhailov-N.;S. A. Dvoretsky
中科院分区：
文献类型：
--
作者：
V. Prudkoglyad;E. Olshanetsky;Z. Kvon;V. Pudalov;N. N. Mikhailov-N.;S. A. Dvoretsky
我们报告的20.5nm宽的碲化汞量子阱的电荷输运性质的系统测量结果在垂直磁场中，流体静压下进行高达15.1千巴。常压下的输运可以用双带半经典模型来描述，而在高压下，我们观察到CNP的电阻率随压力的非单调变化。对于低于$\approx9$ kbar的压力，电阻率的增长与压力，在雅阁与预期的能带结构计算和模型，将在二维半金属与间接带重叠的传输无序的影响。对于更高的压力，电阻率饱和，并在压力进一步增加时开始下降。在约14千巴以上，电阻和跳跃输运特性急剧变化，这可能表明激子绝缘体态的形成。数据还揭示了无序对具有小能带重叠的2D电子-空穴系统中输运的强烈影响。
We report results of systematic measurements of charge transport properties of the 20.5nm wide HgTe-based quantum well in perpendicular magnetic field, performed under hydrostatic pressures up to 15.1 kbar. At ambient pressure transport is well described by the two-band semiclassical model.In contrast, at elevated pressure, we observed non-monotonic pressure dependence of resistivity at CNP. For pressures lower than $\approx9$ kbar, resistivity grows with pressure, in accord with expectations from the band structure calculations and the model incorporating effects of disorder on transport in 2D semimetals with indirect band overlap. For higher pressures, the resistivity saturates and starts decreasing upon further increase of pressure. Above $\approx14$ kbar the resistance and hopping transport character sharply change, which may indicate formation of the excitonic insulator state. The data also reveals strong influence of disorder on transport in 2D electron-hole system with a small band overlap.