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Ultrafast dynamics in the Sb doped MnBi<sub>2</sub>Te<sub>4</sub> magnetic topological insulator

POSTER

Abstract

MnBi2Te4 is recently identified as an intrinsic antiferromagnetic (AFM) topological insulator which is considered as a suitable material for the study of novel topological quantum phenomena whose possible behavior and ultrafast dynamics could be investigated through a versatile femtosecond time-resolved spectroscopy under applied magnetic field and temperature. In this work, topological quantum phase transition is studied in the magnetic topological insulator, MnBi2-xSbxTe4 (x=0.19), which is MnBi2Te4 mixed with antimony. It focusses on the phase transition induced by chemical substitution, magnetic field, and ultrafast lasers. The optical pump-probe (OP-OP) measurements are performed in the magneto-optical closed-cycle cryostat (Opti-Cool) to reveal and study the ultrafast dynamics about MnBi2-xSbxTe4 (x=0.19) at room temperature and low temperature (2 K). A continuously increasing magnetic field upto 7 T is also applied during the low temperature condition to observe the changing ultrafast dynamics crossing the spin-flop situation. In addition, we also plan to perform the Superconducting Quantum Interference Device (SQUID) to confirm the magnetic moment of anti-ferromagnetic (AFM) state at Neel temperature and magnetic level for the origin of spin-flop situation.

Presenters

  • Chi-Chen Tsai

    National Yang Ming Chiao Tung University, National Yang Ming Chiao Tung University, Hsinchu, Taiwan

Authors

  • Chi-Chen Tsai

    National Yang Ming Chiao Tung University, National Yang Ming Chiao Tung University, Hsinchu, Taiwan

  • Jiunn-Yuan Lin

    National Yang Ming Chiao Tung University, National Yang Ming Chiao Tung University, Hsinchu, Taiwan

  • Chih-Wei Luo

    National Yang Ming Chiao Tung University, National Yang Ming Chiao Tung University, Hsinchu, Taiwan

  • Nidhi Puri

    National Yang Ming Chiao Tung University, National Yang Ming Chiao Tung University, Hsinchu, Taiwan

  • Wen-Yen Tzeng

    National Yang Ming Chiao Tung University, National Yang Ming Chiao Tung University, Hsinchu, Taiwan, Department of Electrophysics, National Yang Ming Chiao Tung University

  • Jiun-Haw Chu

    University of Washington, University of Washington, Seattle, Washington, USA

  • Cheng-Chien Chen

    University of Alabama at Birmingham, University of Alabama at Birmingham, Birmingham, Alabama, USA