Abstract
The epitaxial growth of quantum materials gives surface scientist new opportunities to study new emergent phenomena in condensed matter physics. In the talk I will discuss three examples: FeSe superconductor, KxFe2-ySe2 superconductor and Bi2Se3/BSCCO heterostructure. Nodal superconductivity and C4 to C2 symmetry breaking are found in FeSe thin film. More interestingly, a FeSe film as thin as one unit cell can reach even higher Tc. The defect-induced bound states in superconducting gap indicates that the superconductivity in single unit cell FeSe has a dx2-dy2 pairing symmetry. For KxFe2-ySe2, phase separation and coexistence of superconductivity and antiferromagnetism are revealed in thin film. Furthermore, a single unit cell KxFe2-ySe2 provides an example of superconductivity in two-leg ladder system. If Bi2Se3 thin film is grown on BSCCO substrate, high temperature s-wave superconductivity is induced on the surface state of Bi2Se3. This proximity effect may lead to topological superconductivity.
Coffee and tea will be served 20 minutes prior to the seminar.