- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Thermopower of a Two-Dimensional Semimetal in a HgTe Quantum Well
摘要： The thermopower in a two-dimensional semimetal existing in HgTe quantum wells 18–21 nm thick has been studied experimentally and theoretically for the first time. It has been found theoretically and experimentally that the thermopower has two components—diffusion and phonon-drag—and that the second component is several times larger than the first. It has been concluded that the electron–hole scattering plays an important role in both mechanisms of the thermopower.
关键词： diffusion,thermopower,HgTe quantum wells,two-dimensional semimetal,phonon-drag,electron–hole scattering
更新于2025-09-09 09:28:46
-
Two-dimensional semimetal in HgTe quantum well under hydrostatic pressure
摘要： We report results of systematic measurements of charge transport properties of the 20.5-nm-wide HgTe-based quantum well in perpendicular magnetic ?eld, 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 nonmonotonic pressure dependence of resistivity at the “charge neutrality point.” For pressures lower than ≈9 kbar, resistivity grows with pressure, in accord with expectations from the band structure calculations and the model incorporating effects of disorder on transport in two-dimensional (2D) semimetals with indirect band overlap. For higher pressures, the resistivity saturates and starts decreasing upon further increase of pressure. Above ≈14 kbar the resistance value and the magnetoresistance character sharply change, which may indicate signi?cant change of electronic structure due to new electronic phase formation or some structural transitions. The data also reveal strong in?uence of disorder on transport in 2D electron-hole system with a small band overlap.
关键词： HgTe quantum well,charge transport,hydrostatic pressure,magnetoresistance,two-dimensional semimetal
更新于2025-09-04 15:30:14