高场水冷磁体上的高精度热电测量装置

拓扑材料是凝聚态物理近些年的一个重要研究领域. 在对拓扑材料的研究中, 利用较强的磁场可以观测到高度局域电子态中出现的新奇量子态与物理效应. 热电效应是指受热材料中的载流子随着温度梯度由高温区往低温区移动时, 所产生的电荷堆积的一种现象. 热电效应是探究强磁场下拓扑材料反常物性的一种非常有效的手段. 然而关于拓扑材料热电效应在强磁场下的研究较少, 这主要是因为水冷磁体上缺乏热电效应的相关表征手段.本文针对水冷磁体在工作时机械振动很强且变场速率快的特点, 改进了传统的热电测量装置, 实现了在水冷磁体中32 T 磁场下高精度的热电测量. 通过对拓扑材料 ZrTe5 和 ZrSiSe 的热电效应进行测量, 验证了该装置的有效性.

High-Precision Thermoelectric Measurement Device in Water-Cooled Magnet under High Magnetic Fields

Recently, topological materials have stimulated unprecedented research interest in condensed matter physics. In the presence of a perpendicular magnetic field and a longitudinal thermal gradient. the diffusion of carriers can produce a longitudinal electric field and a transverse electric field? which are defined as thermoelectric effects, in principle. thermoelectric effects are sensitive and promising probes to novel quantum states and exotic physical effects for those topological materials. However the studies of thermoelectric properties in ultra-high magnetic fields are rare. In this work, aiming at the problems of fast field-sweeping rate and large mechanical vibration* we have designed and constructed a high-precision measurement device for detecting the thermoelectric effect in water-cooled magnet up to 32 T. Meanwhile, the reliability of our measurement system is further confirmed by measuring the thermoelectric effects for several topological materials.