TY - JOUR
T1 - Ultrafast Electronic Band Gap Control in an Excitonic Insulator
AU - Mor, Selene
AU - Herzog, Marc
AU - GoleŽ, Denis
AU - Werner, Philipp
AU - Eckstein, Martin
AU - Katayama, Naoyuki
AU - Nohara, Minoru
AU - Takagi, Hide
AU - Mizokawa, Takashi
AU - Monney, Claude
AU - Stähler, Julia
N1 - Publisher Copyright:
© 2017 American Physical Society.
PY - 2017/8/23
Y1 - 2017/8/23
N2 - We report on the nonequilibrium dynamics of the electronic structure of the layered semiconductor Ta2NiSe5 investigated by time- and angle-resolved photoelectron spectroscopy. We show that below the critical excitation density of FC=0.2 mJ cm-2, the band gap narrows transiently, while it is enhanced above FC. Hartree-Fock calculations reveal that this effect can be explained by the presence of the low-temperature excitonic insulator phase of Ta2NiSe5, whose order parameter is connected to the gap size. This work demonstrates the ability to manipulate the band gap of Ta2NiSe5 with light on the femtosecond time scale.
AB - We report on the nonequilibrium dynamics of the electronic structure of the layered semiconductor Ta2NiSe5 investigated by time- and angle-resolved photoelectron spectroscopy. We show that below the critical excitation density of FC=0.2 mJ cm-2, the band gap narrows transiently, while it is enhanced above FC. Hartree-Fock calculations reveal that this effect can be explained by the presence of the low-temperature excitonic insulator phase of Ta2NiSe5, whose order parameter is connected to the gap size. This work demonstrates the ability to manipulate the band gap of Ta2NiSe5 with light on the femtosecond time scale.
UR - http://www.scopus.com/inward/record.url?scp=85029216244&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85029216244&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.119.086401
DO - 10.1103/PhysRevLett.119.086401
M3 - Article
C2 - 28952776
AN - SCOPUS:85029216244
SN - 0031-9007
VL - 119
JO - Physical Review Letters
JF - Physical Review Letters
IS - 8
M1 - 086401
ER -