High-temperature superconductivity in one-unit-cell FeSe films.
Since the dramatic enhancement of the superconducting transition temperature (Tc) was reported in a one-unit-cell FeSe film grown on a SrTiO3substrate (1-UC FeSe/STO) by molecular beam epitaxy (MBE), related research on this system has become a new frontier in condensed matter physics. In this paper, we present a brief review on this rapidly developing field, mainly focusing on the superconducting properties of 1-UC FeSe/STO. Experimental evidence for high-temperature superconductivity in 1-UC FeSe/STO, including direct evidence revealed by transport and diamagnetic measurements, as well as other evidence from scanning tunneling microscopy (STM) and angle-resolved photoemission spectroscopy (ARPES), are overviewed. The potential mechanisms of the enhanced superconductivity are also discussed. There are accumulating arguments to suggest that the strengthened Cooper pairing in 1-UC FeSe/STO originates from the interface effects, specifically the charge transfer and coupling to phonon modes in the TiO2plane. The study of superconductivity in 1-UC FeSe/STO not only sheds new light on the mechanism of high-temperature superconductors with layered structures, but also provides an insight into the exploration of new superconductors by interface engineering.
International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, People's Republic of China.
Ziqiao
Z
Wang
Chaofei
C
Liu
Yi
Y
Liu
Jian
J
Wang