Quantum Topological Materials 

  • Credit: Ella Maru Studio

    Unconventional ferroelectricity in moiré heterostructures

    Surprising observation of emergent ferroelectricity in graphene-based moiré heterostructures. Left Credit: Ella Maru Studio

  • Observation of nonlinear Hall effect

    A new type of Hall effect and provide a way of detecting Berry curvature in nonmagnetic quantum materials

  • Spontaneous gyrotropic electronic order

    Realization of optical chiral induction and the observation of a gyrotropically ordered phase in the TMD semimetal

  • Observation of circular photogalvanic effect in monolayer WTe2

    An electrically switchable Berry curvature dipole may facilitate the observation of a wide range of quantum phenomena

Welcome to Dr. Su-Yang Xu's quantum materials research group in the Department of Chemistry and Chemical Biology (CCB) at Harvard. Dr. Xu officially join CCB in January 2020. 

After obtaining his bachelor's degree from Peking University in China, Dr. Xu joined Prof. Zahid Hasan's group at Princeton.  In Prof. Zahid Hasan's group (Link), Dr. Xu became an expert on Angle-Resolved Photoemission Spectroscopy (ARPES), which is a powerful tool to directly visualize the electronic band structures of materials.  His research with Prof. Zahid Hasan on Weyl semimetals was named a Top-10 breakthrough of the year by PhysicsWorld. Dr. Xu then joined Prof. Nuh Gedik's group at MIT as a postdoc researcher in 2016. In Prof. Nuh Gedik's group (Link) and in close collaboration with Prof. Pablo Jarillo-Herrero (Link), Dr. Xu has obtained skills on optical/THz spectroscopy, electronic/optoelectronic transport and 2D material fabrication. His recent works have sparkled great interest of studying nonlinear electronic responses in topological materials (See recent publication). 

Over the past decade, Dr. Xu has published more than 100 peer-reviewed research articles, including 5 in Science, 3 in Nature, 10 in Nature Physics, 3 in Nature Materials, 1 in Nature Nanotechnology, 12 in Nature Communications, 4 in Science Advances and 8 in Physical Review Letters. Dr. Xu has been cited over 14,000 times (Google Scholar page) and continuously selected as one of the Clarivate Analytics highly cited researchers since 2016 (Link).

Dr. Xu has a broad interest in electronic and optical properties in quantum matters, with the particular emphasis on emergent quantum phenomena, such as topological and broken symmetry states. Combining the versatile tools that will be developed in the TopoXu LAB and powerful facilities provided by National Labs and worldwide beamlines, the Xu group will explore and uncover the stunning beauty of quantum crystals. 

Moreover, the Xu group thoroughly respect and appreciate the power of interdisciplinary approaches and synergetic efforts. The group will take on Dr. Xu's strong collaborative ties around the world to solve the challenges in fundamental science, as well as in clean energy, low-power electronics, quantum computing, etc. Housed in the Department of Chemistry and Chemical Biology, the beautiful and natural synergy among physics, chemistry and biology will sparkle new understanding, new ideas, new science and technology (See research).