Antiferromagnetic FeSe monolayer on SrTiO3: The charge doping and electric field effects

作者：Zheng Fawei^*; Wang Zhigang; Kang Wei; Zhang Ping

来源：Scientific Reports, 2013, 3(1): 2213.

DOI：10.1038/srep02213

By growing monolayer FeSe on SrTiO3(001) surface, researchers obtain the highest superconducting transition-temperature for iron-based superconductor. Here, we study the antiferromagnetic (AFM) checkerboard monolayer FeSe adsorbed on SrTiO3(001) surface. We show that the system has a considerable charge transfer from SrTiO3(001) substrate to FeSe monolayer, and so has a self-constructed electric field. The FeSe monolayer band structure near the Brillouin zone (BZ) center is sensitive to charge doping, and the spin-resolved energy bands at BZ corner are distorted to be flattened by the perpendicular electric field. It is revealed that the striking disappearance of the Fermi surface around the BZ center can be well explained by the AFM checkerboard phase with charge doping and electric field effects. We propose a tight-binding model Hamiltonian to take these key factors into account. We also show that this composite structure is an ideal electron-hole bilayer system, with electrons and holes respectively formed in FeSe monolayer and TiO2 surface layer.

• 出版日期2013-7-18
• 单位北京计算科学研究中心; 北京大学