TY - JOUR
T1 - Nonequilibrium dynamics in the pump-probe spectroscopy of excitonic insulators
AU - Tanabe, Tetsuhiro
AU - Sugimoto, Koudai
AU - Ohta, Yukinori
N1 - Funding Information:
T.T. acknowledges support by a Chiba University SEEDS Fund. This work was supported in part by a Grant-in-Aid for Scientific Research (No. JP17K05530) from JSPS of Japan.
Funding Information:
We thank T. Kaneko, T. Mizokawa, Y. Murakami, K. Okazaki, Y. Yamada, and K. Yonemitsu for enlightening discussions. T.T. acknowledges support by a Chiba University SEEDS Fund. This work was supported in part by a Grant-in-Aid for Scientific Research (No. JP17K05530) from JSPS of Japan.
Publisher Copyright:
© 2018 American Physical Society.
PY - 2018/12/12
Y1 - 2018/12/12
N2 - We study the nonequilibrium dynamics in the pump-probe spectroscopy of excitonic insulators using the spinless two-orbital model with phonon degrees of freedom in the time-dependent mean-field approximation. We introduce the pulse light as a time-dependent vector potential via the Peierls phase in the Hamiltonian. We find that, in the Bose-Einstein condensation regime where the normal state is semiconducting, the excitonic order is suppressed when the frequency of the pulse light is slightly larger than the band gap, while the order is enhanced when the frequency of the pulse is much larger than the band gap. We moreover find that the excitonic order is completely destroyed in the former situation if the intensity of the pulse is sufficiently strong. In the BCS regime where the normal state is semimetallic, we find that the excitonic order is always suppressed, irrespective of the frequency of the pulse light. The quasiparticle band structure and optical conductivity spectrum after the pumping are also calculated for the instantaneous states.
AB - We study the nonequilibrium dynamics in the pump-probe spectroscopy of excitonic insulators using the spinless two-orbital model with phonon degrees of freedom in the time-dependent mean-field approximation. We introduce the pulse light as a time-dependent vector potential via the Peierls phase in the Hamiltonian. We find that, in the Bose-Einstein condensation regime where the normal state is semiconducting, the excitonic order is suppressed when the frequency of the pulse light is slightly larger than the band gap, while the order is enhanced when the frequency of the pulse is much larger than the band gap. We moreover find that the excitonic order is completely destroyed in the former situation if the intensity of the pulse is sufficiently strong. In the BCS regime where the normal state is semimetallic, we find that the excitonic order is always suppressed, irrespective of the frequency of the pulse light. The quasiparticle band structure and optical conductivity spectrum after the pumping are also calculated for the instantaneous states.
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U2 - 10.1103/PhysRevB.98.235127
DO - 10.1103/PhysRevB.98.235127
M3 - Article
AN - SCOPUS:85058282883
SN - 2469-9950
VL - 98
JO - Physical Review B
JF - Physical Review B
IS - 23
M1 - 235127
ER -