2D topological insulator

Topological quantum matters and phenomena in epitaxial low-dimensional structures

 The goals of our research are to:

l  Experimentally discover topological quantum phenomena such as topological superconductivity and topological magnetoelectric effect.

l  Find superior topological materials for the quantum anomalous Hall effect and quantum spin Hall effect.

l  Apply topological quantum matters and phenomena in electronic, spintronic, thermoelectric, magnetoelectric, and photoelectric materials and devices.

Our approaches to these goals are to:

l  Combining molecular beam epitaxy (MBE), angle-resolved photoemission spectroscopy (ARPES) and scanning tunneling microscopy (STM) to prepare and engineer thin films and heterostructures of topological materials.

l  Realizing and studying quantum phenomena in the films and heterostructures by utilizing transport measurements and microfabrication techniques.

Our main achievements:

Ø  The first experimental discovery of the quantum anomalous Hall effect.

     Science 340, 167 (2013); Phys. Rev. Lett. 115, 126801 (2015)

Ø  MBE growth and energy band engineering of high quality topological insulator films.

     Adv. Mater. 22, 4002 (2010); Nature Phys. 6, 584 (2010); Nature Commun. 2, 574 (2011);

     Phys. Rev. Lett. 112, 186801 (2014); Phys. Rev. Lett. 115, 136801 (2015); Adv. Mater. 27, 4150 (2015)

Ø  Observations of novel properties and quantum phenomena in topological insulator films. 

     Phys. Rev. Lett. 103, 266803 (2009); Phys. Rev. Lett. 105, 076801 (2010); Phys. Rev. Lett. 108, 016401 (2012);

     Phys. Rev. Lett. 108, 066809 (2012); Phys. Rev. Lett. 114, 176602 (2015)

Ø  Understandings on magnetic and magneto-transport properties of magnetically doped topological insulators.

     Phys. Rev. Lett. 108, 036805 (2012); Adv. Mater. 25, 1065 (2013); Science 339, 1582 (2013);

     Phys. Rev. Lett. 112, 056801 (2014); Nature Commun. 5, 4915 (2014)