Topological quantum magnets are materials whose properties are determined by the coupling between magnetism and nontrivial band topology. These materials carry dissipationless surface and edge currents which are promising for quantum information and spintronic applications with low dissipation. Topological quantum magnets show giant transverse transport effects caused by the Berry curvature arising from the nontrivial topology of the electronic band structure in the momentum space. In some cases, nonvanishing real space Berry curvature can emerge in these quantum magnets due to non-collinear magnetic configuration which often has a nonzero scalar spin chirality. Recently discovered topological quantum magnets such as Dirac and Weyl semimetals host relativistic fermio ns which enable observation of high energy physics phenomena such as the chiral anomaly and mixed axialâ€“gravitational anomaly in condensed matter physics. Until now only a handful of materials have been experimentally validated to be magnetic Weyl semimetals. Furthermore, most of the present study is limited to bulk samples and device applications of these materials are scarce. In this talk, I will primarily focus on recently discovered antiferromagnetic Weyl semimetal Mn3Sn. Although it is an antiferromagnet with negligible net magnetization combined effect of large Berry curvature and multipoles leads to large macroscopic transverse responses such as the anomalous Hall and Nernst effects, the magneto-optical effect, and the novel magnetic spin Hall effect. In particular, I will present our recent discovery of the magnetic spin Hall effect in Mn3Sn using nanoscale spintronic devices.
Dr. Prasanta Kumar Muduli obtained his Ph.D. in Physics from IIT, Kanpur, India. After his Ph.D., he worked as a postdoctoral researcher at Leipzig University (Germany), University of Cambridge (UK), University of Tokyo (Japan), and TU Dresden (Germany). He is an experimental condensed matter physicist working on various kinds of nanoscale quantum devices using magnetic, superconducting, and 2D materials. His present research is geared towards developing quantum technologies that exploit topological bulk and surface electronic states of recently discovered quantum materials. He specializes in various types of thin-film growth and device fabrication using advanced micro-and nano-fabrication techniques. Recently he started working as an assistant professor in the Department of Physics at IIT Madras, India.