Nakamura Daisuke, Adachi Tadashi, Omori Keisuke, Koike Yoji, Takeyama Shojiro
Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8581, Japan.
Department of Engineering and Applied Sciences, Sophia University, 7-1 Kioicho, Chiyoda-ku, Tokyo, 102-8554, Japan.
Sci Rep. 2019 Nov 18;9(1):16949. doi: 10.1038/s41598-019-52973-1.
The upper critical field of a cuprate high-temperature superconductor, LaSrCuO, was investigated by high-frequency self-resonant contactless electrical conductivity measurements in magnetic fields up to 102 T. An irreversible transition was observed at 85 T (T = 4.2 K), defined as the upper critical field. The temperature-dependent upper critical field was argued on the basis of the Werthamer-Helfand-Hohenberg theory. The Pauli-limiting pair-breaking process with a small contribution of the spin-orbit coupling explained the first-order phase transition exhibiting a hysteresis observed at low temperatures.
通过在高达102 T的磁场中进行高频自谐振非接触电导率测量，研究了铜酸盐高温超导体LaSrCuO的上临界场。在85 T（T = 4.2 K）处观察到不可逆转变，将其定义为上临界场。基于韦特哈默 - 赫尔方德 - 霍恩伯格理论讨论了与温度相关的上临界场。具有小自旋 - 轨道耦合贡献的泡利极限对破坏过程解释了在低温下观察到的呈现磁滞的一级相变。
