Magnetoresistance Measurement of Topological Quantum Materials in Pulsed High Magnetic Field

Abstract

Recently a series of new topological materials, such as topological insulator, topological semimetal, topological superconductor have been discovered through a large number of magneto-transport measurements in high magnetic field, which greatly promotes the research process of topological quantum materials. The physical properties such as SdH oscillations can be observed from accurately measuring the magnetoresistance effect. The experimental environment puts higher requirements for data acquisition and processing procedures in topological materials measurements for the characteristics of high noise and short discharge time in pulsed high magnetic field. However, the references rarely mentions the related solutions. In this paper, a complete set of detection methods and data processing strategies for topological materials in pulsed high magnetic field environment are proposed. Here we introduce a digital lock-in amplifier and optimize the parameters of FIR filters. Based on NI-PXI-5105 and Labview, the model of fast auto-detection digital lock-in system is carried out. Taking the WTe 2 sample to experiment, the magneto-resistance detection and data analysis were performed in 65T pulsed magnetic field. A clear magnetoresistance curve with the significant SdH quantum oscillation at different temperatures was obtained. The results proved that this method is effective and applicable to complete the measurement technology of topological quantum materials in high magnetic field.