The magnetic susceptibility of two-dimensional systems in the limit of low fields can hardly be detected by magnetometric measurements because it is difficult to separate the contributions from the substrate and two-dimensional gas for the magnetization not oscillating with the field. The derivative of the magnetization with respect to the carrier density in two-dimensional systems in narrow (thickness <7 nm) HgTe quantum wells has been measured in this work by means of the modulation of the chemical potential by a magnetic field perpendicular to the system plane. It was previously established that the spectrum of the valence band of such quantum wells contains not only easy Dirac states in the center of the Brillouin zone but also heavy hole valleys with maxima shifted from the center in the [331] direction. It has been found that the magnetic susceptibility drops sharply as the Fermi level leaves these heavy valleys with the addition of electrons to the system. This behavior can be interpreted either as the weakening of paramagnetism or as the enhancement of diamagnetism. The estimates obtained show that the observed effect is due primarily to the paramagnetism of states in the heavy valleys of the valence band.

中文翻译：

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垂直磁场中HgTe量子阱中的磁化率测量

二维系统在低磁场范围内的磁化率很难通过磁力测量来检测，因为很难将来自基板和二维气体的贡献分开，以使磁化强度不会随磁场而振荡。在这项工作中，借助于垂直于系统的磁场对化学势的调制，已经测量了在窄（厚度<7 nm）HgTe量子阱中二维系统中磁化强度相对于载流子密度的导数。飞机。先前已经确定，这种量子阱的价带谱不仅在布里渊区的中心包含容易的狄拉克态，而且还包含重的空穴谷，其最大值从[331]方向偏离中心。已经发现，随着费米能级离开这些沉重的谷并向系统添加电子，磁化率急剧下降。这种行为可以解释为顺磁性的减弱或反磁性的增强。获得的估计表明，观察到的影响主要是由于价带大谷中的状态的顺磁性引起的。