Time: 10:00 am, 25 August, 2020

Speaker: Dr. Xiaoran Liu, Rutgers University

Abstract: 

The interplay between electron-electron correlations and strong spin-orbit coupling has lead to tremendous predictions for correlated topological states of matter. As the archetypal candidates for magnetic Weyl semimetal, the pyrochlore iridates have been proposed to host more exotic topological phases in their thin films, manifested as the emergence of zero-field Hall conductance induced by the Berry curvature of bands. In this talk, I will show combined experimental and theoretical evidences for the observation of these emergent topological states in high-quality (111) pyrochlore iridate thin films, where intrinsic anomalous Hall effect with extremely large coercivity is demonstrated on the low-temperature magnetic phase with the peculiar all-in-all-out antiferromagnetic ordering. The nontrivial band topology is revealed as a result of the surface state induced by the termination of the film. These results highlight the intrinsic bulk-surface correspondence of the Ir sublattice in pyrochlore and open new directions for novel correlated topological materials.

Brief CV of Dr. Xiaoran Liu: 

Dr. Xiaoran Liu received his bachelor in materials science and engineering from Nanjing University. Then he went to University of Arkansas and got his PhD in Physics there. After that, he joined Rutgers University as a named postdoctoral fellow funded by the Gordon and Betty Moore foundation. Xiaoran Liu’s research interest is mainly in the design and fabrication of high-quality thin films and heterojunctions of novel quantum materials, where interesting electronic, magnetic, optical, and/or topological phenomena take place. In addition, he is also interested in studying novel bulk quantum materials by means of state-of-the-art characterization tools such as synchrotron/neutron-based techniques.