Iwasa Ayumu, Kondo Akihiro, Kawachi Shiro, Akiba Kazuto, Nakanishi Yoshiki, Yoshizawa Masahito, Tokunaga Masashi, Kindo Koichi
Institute for Solid State Physics (ISSP), The University of Tokyo, Kashiwa, Chiba, 277-8581, Japan.
Graduate School of Arts and Science, Iwate University, Morioka, Iwate, 020-8551, Japan.
Sci Rep. 2019 Feb 8;9(1):1672. doi: 10.1038/s41598-018-38206-x.
We investigated the fundamental physical properties in the ultra-quantum limit state of bismuth through measurements of magnetoresistance, magnetization, magnetostriction, and ultrasound attenuation in magnetic fields up to 60T. For magnetic fields applied along the bisectrix direction of a single crystal, a drastic sign reversal in magnetostriction was observed at approximately 39T, which could be ascribed to the complete valley polarization in the electron Fermi pockets. The application of magnetic fields along the binary direction presented an anomalous feature at approximately 50T only in the magnetoresistance. The emergence of a field-induced splitting of a valley was proposed as a possible origin of this anomaly.
我们通过在高达60T的磁场中测量磁阻、磁化强度、磁致伸缩和超声衰减，研究了铋在超量子极限状态下的基本物理性质。对于沿单晶二等分线方向施加的磁场，在约39T处观察到磁致伸缩的急剧符号反转，这可归因于电子费米口袋中的完全谷极化。沿二元方向施加磁场时，仅在磁阻中约50T处出现异常特征。提出谷的场致分裂的出现可能是这种异常现象产生的原因。
