Direct observations of the photoinduced change in dimerization in K-TCNQ

Tadahiko Ishikawa, Ryosuke Hosoda, Yoichi Okimoto, Sei'Ichi Tanaka, Ken Onda, Shinya Koshihara, Reiji Kumai

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

The photoinduced dynamics of a potassium-tetracyanoquinodimethane (K-TCNQ) single crystal in the generalized Peierls phase are evaluated via time-resolved vibrational spectroscopy. The transient reflectivity spectrum of the photoinduced state in the mid-IR range shows a decrease in the height and width of the reflectivity band because of the electron-molecular-vibration-coupled CN stretching mode at approximately 2180 cm-1. This spectral change suggests that the photoexcitation of the charge transfer in TCNQ molecules induces melting of the dimerization of the molecules. From detailed analysis of the spectral evolution, the relaxation time constant from the photoinduced state to the dimerized state is estimated to be approximately 0.6 ps. Even after the recovery of the dimerization, a fluctuation is still observed, probably because of a domain-wall soliton. The fluctuation gradually dissipates with a time constant of approximately 2.3 ps. Direct observation of the dimerization process reveals the true dynamics of the photoinduced cooperative phenomenon within this system.

Original languageEnglish
Article number195130
JournalPhysical Review B
Volume93
Issue number19
DOIs
Publication statusPublished - May 17 2016

Fingerprint

Dimerization
dimerization
time constant
Molecular vibrations
reflectance
Vibrational spectroscopy
Molecules
Photoexcitation
Domain walls
Solitons
photoexcitation
Relaxation time
Stretching
domain wall
Potassium
Charge transfer
molecules
potassium
Melting
solitary waves

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

Ishikawa, T., Hosoda, R., Okimoto, Y., Tanaka, SI., Onda, K., Koshihara, S., & Kumai, R. (2016). Direct observations of the photoinduced change in dimerization in K-TCNQ. Physical Review B, 93(19), [195130]. https://doi.org/10.1103/PhysRevB.93.195130

Direct observations of the photoinduced change in dimerization in K-TCNQ. / Ishikawa, Tadahiko; Hosoda, Ryosuke; Okimoto, Yoichi; Tanaka, Sei'Ichi; Onda, Ken; Koshihara, Shinya; Kumai, Reiji.

In: Physical Review B, Vol. 93, No. 19, 195130, 17.05.2016.

Research output: Contribution to journalArticle

Ishikawa, T, Hosoda, R, Okimoto, Y, Tanaka, SI, Onda, K, Koshihara, S & Kumai, R 2016, 'Direct observations of the photoinduced change in dimerization in K-TCNQ', Physical Review B, vol. 93, no. 19, 195130. https://doi.org/10.1103/PhysRevB.93.195130
Ishikawa T, Hosoda R, Okimoto Y, Tanaka SI, Onda K, Koshihara S et al. Direct observations of the photoinduced change in dimerization in K-TCNQ. Physical Review B. 2016 May 17;93(19). 195130. https://doi.org/10.1103/PhysRevB.93.195130
Ishikawa, Tadahiko ; Hosoda, Ryosuke ; Okimoto, Yoichi ; Tanaka, Sei'Ichi ; Onda, Ken ; Koshihara, Shinya ; Kumai, Reiji. / Direct observations of the photoinduced change in dimerization in K-TCNQ. In: Physical Review B. 2016 ; Vol. 93, No. 19.
@article{82c8084f0bb74d80a229376e5fc19647,
title = "Direct observations of the photoinduced change in dimerization in K-TCNQ",
abstract = "The photoinduced dynamics of a potassium-tetracyanoquinodimethane (K-TCNQ) single crystal in the generalized Peierls phase are evaluated via time-resolved vibrational spectroscopy. The transient reflectivity spectrum of the photoinduced state in the mid-IR range shows a decrease in the height and width of the reflectivity band because of the electron-molecular-vibration-coupled CN stretching mode at approximately 2180 cm-1. This spectral change suggests that the photoexcitation of the charge transfer in TCNQ molecules induces melting of the dimerization of the molecules. From detailed analysis of the spectral evolution, the relaxation time constant from the photoinduced state to the dimerized state is estimated to be approximately 0.6 ps. Even after the recovery of the dimerization, a fluctuation is still observed, probably because of a domain-wall soliton. The fluctuation gradually dissipates with a time constant of approximately 2.3 ps. Direct observation of the dimerization process reveals the true dynamics of the photoinduced cooperative phenomenon within this system.",
author = "Tadahiko Ishikawa and Ryosuke Hosoda and Yoichi Okimoto and Sei'Ichi Tanaka and Ken Onda and Shinya Koshihara and Reiji Kumai",
year = "2016",
month = "5",
day = "17",
doi = "10.1103/PhysRevB.93.195130",
language = "English",
volume = "93",
journal = "Physical Review B",
issn = "2469-9950",
publisher = "American Physical Society",
number = "19",

}

TY - JOUR

T1 - Direct observations of the photoinduced change in dimerization in K-TCNQ

AU - Ishikawa, Tadahiko

AU - Hosoda, Ryosuke

AU - Okimoto, Yoichi

AU - Tanaka, Sei'Ichi

AU - Onda, Ken

AU - Koshihara, Shinya

AU - Kumai, Reiji

PY - 2016/5/17

Y1 - 2016/5/17

N2 - The photoinduced dynamics of a potassium-tetracyanoquinodimethane (K-TCNQ) single crystal in the generalized Peierls phase are evaluated via time-resolved vibrational spectroscopy. The transient reflectivity spectrum of the photoinduced state in the mid-IR range shows a decrease in the height and width of the reflectivity band because of the electron-molecular-vibration-coupled CN stretching mode at approximately 2180 cm-1. This spectral change suggests that the photoexcitation of the charge transfer in TCNQ molecules induces melting of the dimerization of the molecules. From detailed analysis of the spectral evolution, the relaxation time constant from the photoinduced state to the dimerized state is estimated to be approximately 0.6 ps. Even after the recovery of the dimerization, a fluctuation is still observed, probably because of a domain-wall soliton. The fluctuation gradually dissipates with a time constant of approximately 2.3 ps. Direct observation of the dimerization process reveals the true dynamics of the photoinduced cooperative phenomenon within this system.

AB - The photoinduced dynamics of a potassium-tetracyanoquinodimethane (K-TCNQ) single crystal in the generalized Peierls phase are evaluated via time-resolved vibrational spectroscopy. The transient reflectivity spectrum of the photoinduced state in the mid-IR range shows a decrease in the height and width of the reflectivity band because of the electron-molecular-vibration-coupled CN stretching mode at approximately 2180 cm-1. This spectral change suggests that the photoexcitation of the charge transfer in TCNQ molecules induces melting of the dimerization of the molecules. From detailed analysis of the spectral evolution, the relaxation time constant from the photoinduced state to the dimerized state is estimated to be approximately 0.6 ps. Even after the recovery of the dimerization, a fluctuation is still observed, probably because of a domain-wall soliton. The fluctuation gradually dissipates with a time constant of approximately 2.3 ps. Direct observation of the dimerization process reveals the true dynamics of the photoinduced cooperative phenomenon within this system.

UR - http://www.scopus.com/inward/record.url?scp=84968724712&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84968724712&partnerID=8YFLogxK

U2 - 10.1103/PhysRevB.93.195130

DO - 10.1103/PhysRevB.93.195130

M3 - Article

VL - 93

JO - Physical Review B

JF - Physical Review B

SN - 2469-9950

IS - 19

M1 - 195130

ER -