摘要
We study theoretically the exciton Bose–Einstein condensation and exciton vortices in a two-dimensional(2 D)perovskite(PEA)2 Pb I4 monolayer.Combining the first-principles calculations and the Keldysh model,the exciton binding energy of in a(PEA)2 Pb I4 monolayer can approach hundreds of me V,which make it possible to observe the excitonic effect at room temperature.Due to the large exciton binding energy,and hence the high density of excitons,we find that the critical temperature of the exciton condensation could approach the liquid nitrogen regime.In the presence of perpendicular electric fields,the dipole-dipole interaction between excitons is found to drive the condensed excitons confined in(PEA)2 Pb I4 monolayer flakes into patterned vortices,as the evolution time of vortex patterns is comparable to the exciton lifetime.
作者
Yingda Chen
Dong Zhang
Kai Chang
陈颖达;张东;常凯(State Key Laboratory for Superlattices and Microstructures,Institute of Semiconductors,Chinese Academy of Sciences,Beijing 100083,China;CAS Center for Excellence in Topological Quantum Computation,University of Chinese Academy of Sciences,Beijing 100190,China;Beijing Academy of Quantum Information Sciences,Beijing 100193,China)
基金
Supported by the National Key R&D Programme of China(Grant Nos.2017YFA0303400 and 2016YFE0110000)
the National Natural Science Foundation of China(Grant Nos.11574303 and 11504366)
the Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2018148)
the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB28000000)。
