We are interested in probing and controlling electronic structures and emergent phenomena in novel quantum matter, including topological quantum materials, unconventional superconductors, two-dimensional (2D) materials, and strongly correlated systems.

   Our previous studies have revealed remarkable electronic and topological properties in these novel materials, including:

   Direct observations of bulk Weyl cones, surface Fermi arcs and their correspondence in transition-metal monophosphides as experimental evidences of the Weyl semimetal [1-3].

   Direct observations of the metallic surface state and its helical spin texture in SmB₆ as evidences of the topological Kondo insulator[4-6].

  With further improvement in both experimental techniques and sample qualities, we aim at exploring more exotic quantum phenomena ranging from correlated topological semimetals to superconductors with unusual mechanism or non-trivial topological properties.

[1]   B.Q.L*, N. Xu*, H.M.W* et. al., “Observation of Weyl nodes in TaAs.” Nature Physics 11, 724-727 (2015).

[2]   N. Xu*^§, H.M.W* et. al., “Observation of Weyl nodes and Fermi arcs in TaP.” Nature Communications 7, 11006 (2016).

[3]   N. Xu^§et. al., Distinct evolutions of Weyl fermion quasiparticles and Fermi arcs with bulk band topology in Weyl semimetals. Physical Review Letters 118, 106406 (2017).

[4]   N. Xu^§et. al., “Surface and bulk electronic structure of the strongly correlated system SmB₆ and implications for a topological Kondo insulator.” Phys. Rev. B 88, 121102(R) (2013);

[5]   N. Xu^§et. al., “Direct observation of the spin texture in SmB₆ as evidence of the topological Kondo insulator.” Nature Communications 5, 4566 (2014).

[6]   N. Xu^§et. al., “Spin- and angle-resolved photoemission on the topological Kondo Insulator candidate: SmB₆”, J. Phys.: Condens. Matter, 28 363001 (2016). (Invited Review article)

      (FIRST*-AUTHOR, CORRESPONDING^§-AUTHOR)