Author(s): Jiang, ZY (Jiang, Zeyu); Lou, WK (Lou, Wenkai); Liu, Y (Liu, Yu); Li, YC (Li, Yuanchang); Song, HF (Song, Haifeng); Chang, K (Chang, Kai); Duan, WH (Duan, Wenhui); Zhang, SB (Zhang, Shengbai)
Source: PHYSICAL REVIEW LETTERS Volume: 124 Issue: 16 Article Number: 166401 DOI: 10.1103/PhysRevLett.124.166401 Published: APR 22 2020
Abstract: While various excitonic insulators have been studied in the literature, due to the perceived too-small spin splitting, spin-triplet excitonic insulator is rare. In two-dimensional systems such as a semihydrogenated graphene (known as graphone), however, it is possible, as revealed by first-principles calculations coupled with Bethe-Salpeter equation. The critical temperature, given by an effective Hamiltonian, is 11.5 K. While detecting excitonic insulators is still a daunting challenge, the condensation of triplet excitons will result in spin superfluidity, which can be directly measured by a transport experiment. Nonlocal dielectric screening also leads to an unexpected phenomenon, namely, an indirect-to-direct transition crossover between single-particle band and exciton dispersion in the semihydrogenated graphene, which offers yet another test by experiment.
Accession Number: WOS:000527527300008
Author Identifiers:
AuthorWeb of Science ResearcherIDORCID Number
Duan, Wenhui H-4992-2011 0000-0001-9685-2547
ISSN: 0031-9007
eISSN: 1079-7114
Full Text: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.124.166401