TY - JOUR
T1 - Coherent Phonon Assisted Ultrafast Order-Parameter Reversal and Hidden Metallic State in Ta2NiSe5
AU - Guan, Mengxue
AU - Chen, Daqiang
AU - Chen, Qing
AU - Yao, Yugui
AU - Meng, Sheng
N1 - Publisher Copyright:
© 2023 American Physical Society.
PY - 2023/12/22
Y1 - 2023/12/22
N2 - The nonequilibrium dynamics during photoinduced insulator-to-metal transition (IMT) in the excitonic insulator (EI) candidate Ta2NiSe5 have been investigated, which reproduce the timescale and spectral features of the ultrafast switch and reveal intricate many-body interactions involving multidegrees of freedom. The key role of lattice order parameter (OP) reversal, occurring on a timescale comparable to that of purely electronic processes (<100 fs), is identified. This reversal is enabled by the anharmonic interactions between EI-OP-coupled phonons and the conventional coherent phonons, leading to a modified potential energy landscape and a high-frequency mode up-conversion. The phonon excitation depends on the dynamics of photocarriers distributed around the Fermi level, and thus intertwines with the excitonic quenching and the complete gap collapse. These findings provide a comprehensive understanding of exciton-phonon dynamics in correlated quantum materials.
AB - The nonequilibrium dynamics during photoinduced insulator-to-metal transition (IMT) in the excitonic insulator (EI) candidate Ta2NiSe5 have been investigated, which reproduce the timescale and spectral features of the ultrafast switch and reveal intricate many-body interactions involving multidegrees of freedom. The key role of lattice order parameter (OP) reversal, occurring on a timescale comparable to that of purely electronic processes (<100 fs), is identified. This reversal is enabled by the anharmonic interactions between EI-OP-coupled phonons and the conventional coherent phonons, leading to a modified potential energy landscape and a high-frequency mode up-conversion. The phonon excitation depends on the dynamics of photocarriers distributed around the Fermi level, and thus intertwines with the excitonic quenching and the complete gap collapse. These findings provide a comprehensive understanding of exciton-phonon dynamics in correlated quantum materials.
UR - http://www.scopus.com/inward/record.url?scp=85180549358&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.131.256503
DO - 10.1103/PhysRevLett.131.256503
M3 - Article
C2 - 38181365
AN - SCOPUS:85180549358
SN - 0031-9007
VL - 131
JO - Physical Review Letters
JF - Physical Review Letters
IS - 25
M1 - 256503
ER -