TY - JOUR
T1 - Half-Excitonic Insulator
T2 - A Single-Spin Bose-Einstein Condensate
AU - Jiang, Zeyu
AU - Li, Yuanchang
AU - Duan, Wenhui
AU - Zhang, Shengbai
N1 - Publisher Copyright:
© 2019 American Physical Society.
PY - 2019/6/14
Y1 - 2019/6/14
N2 - First-principles calculations reveal an unusual electronic state (dubbed as half excitonic insulator) in monolayer 1T-MX2 (M=Co, Ni and X=Cl, Br). Its one spin channel has a many-body ground state due to excitonic instability, while the other is characterized by a conventional band insulator gap. This disparity arises from a competition between the band gap and exciton binding energy, which exhibits a spin dependence due to different orbital occupations. Such a state can be identified by optical absorption measurements and angle-resolved photoemission spectroscopy. Our theory not only provides new insights for the study of exciton condensation in magnetic materials but also suggests that strongly correlated materials could be fertile candidates for excitonic insulators.
AB - First-principles calculations reveal an unusual electronic state (dubbed as half excitonic insulator) in monolayer 1T-MX2 (M=Co, Ni and X=Cl, Br). Its one spin channel has a many-body ground state due to excitonic instability, while the other is characterized by a conventional band insulator gap. This disparity arises from a competition between the band gap and exciton binding energy, which exhibits a spin dependence due to different orbital occupations. Such a state can be identified by optical absorption measurements and angle-resolved photoemission spectroscopy. Our theory not only provides new insights for the study of exciton condensation in magnetic materials but also suggests that strongly correlated materials could be fertile candidates for excitonic insulators.
UR - http://www.scopus.com/inward/record.url?scp=85067364689&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.122.236402
DO - 10.1103/PhysRevLett.122.236402
M3 - Article
C2 - 31298916
AN - SCOPUS:85067364689
SN - 0031-9007
VL - 122
JO - Physical Review Letters
JF - Physical Review Letters
IS - 23
M1 - 236402
ER -