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Title: The time of a photoinduced spin-Peierls phase transition

Abstract

The time τ of the spin-Peierls phase transition is analyzed theoretically as a function of the duration τ{sub p} of the exciting light pulse and the average number x{sub 0} of absorbed photons per magnetic ion after the transmission of the pulse. It is shown that the phase transition occurs at x{sub 0} > x{sub c}. The critical value x{sub c} is determined as a function of the duration τ{sub p} of the light pulse. A photoinduced variation in the optical reflection coefficient R is calculated as a function of time t. The results of calculation are compared with experimental data on ultrafast photoinduced melting of the low-temperature spin-Peierls phase into potassium tetracyanoquinodimethan (K-TCNQ)

Authors:
 [1]
  1. Ulyanovsk State University (Russian Federation)
Publication Date:
OSTI Identifier:
22472390
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Experimental and Theoretical Physics; Journal Volume: 120; Journal Issue: 2; Other Information: Copyright (c) 2015 Pleiades Publishing, Inc.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COMPARATIVE EVALUATIONS; ELECTROMAGNETIC PULSES; MELTING; OPTICAL REFLECTION; PHASE TRANSFORMATIONS; PHOTONS; POTASSIUM COMPOUNDS; QUINONES; SPIN; TEMPERATURE DEPENDENCE; TIME DEPENDENCE; VARIATIONS; VISIBLE RADIATION

Citation Formats

Semenov, A. L., E-mail: smnv@mail.ru. The time of a photoinduced spin-Peierls phase transition. United States: N. p., 2015. Web. doi:10.1134/S1063776115020041.
Semenov, A. L., E-mail: smnv@mail.ru. The time of a photoinduced spin-Peierls phase transition. United States. doi:10.1134/S1063776115020041.
Semenov, A. L., E-mail: smnv@mail.ru. Sun . "The time of a photoinduced spin-Peierls phase transition". United States. doi:10.1134/S1063776115020041.
@article{osti_22472390,
title = {The time of a photoinduced spin-Peierls phase transition},
author = {Semenov, A. L., E-mail: smnv@mail.ru},
abstractNote = {The time τ of the spin-Peierls phase transition is analyzed theoretically as a function of the duration τ{sub p} of the exciting light pulse and the average number x{sub 0} of absorbed photons per magnetic ion after the transmission of the pulse. It is shown that the phase transition occurs at x{sub 0} > x{sub c}. The critical value x{sub c} is determined as a function of the duration τ{sub p} of the light pulse. A photoinduced variation in the optical reflection coefficient R is calculated as a function of time t. The results of calculation are compared with experimental data on ultrafast photoinduced melting of the low-temperature spin-Peierls phase into potassium tetracyanoquinodimethan (K-TCNQ)},
doi = {10.1134/S1063776115020041},
journal = {Journal of Experimental and Theoretical Physics},
number = 2,
volume = 120,
place = {United States},
year = {Sun Feb 15 00:00:00 EST 2015},
month = {Sun Feb 15 00:00:00 EST 2015}
}
  • The dynamical equation for the order parameter of the metal-semiconductor phase transition, as well as the kinetic equation for the density of nonequilibrium electron-hole pairs of a Peierls system in a light field, has been derived. An expression for the time {tau} of the nonthermal photoinduced semiconductor-metal phase transition has been obtained from these equations for the case of an ultrashort light pulse. It has been shown that, to initiate the phase transition, the energy density W of the light pulse must be higher than the critical value W{sub c}. The W{sub c}, {tau}, and optical absorption coefficient {gamma}{sub 0}more » that are calculated in the framework of the proposed model are in agreement with the experimental data (W{sub c} {approx} 12 mJ/cm{sup 2}, {tau} {approx} 75 fs, and {gamma}{sub 0} {approx} 10{sup 5} cm{sup -1}) on the irradiation of a vanadium dioxide film by a laser pulse with a duration of {tau}{sub p} {approx} 15 fs, a photon energy of {Dirac_h}{theta}{sub 0} = 1.6 eV, and an energy density of W = 50 mJ/cm{sup 2}.« less
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