Measurement of a photoinduced transition from a nonordered phase to a transient ordered phase in the organic quantum-paraelectric compound dimethyltetrathiafulvalene-dibromodichloro-p-benzoquinone using femtosecond laser irradiation.
We report a new photoinduced transition from a nonordered phase to a transient ordered phase with symmetry breaking in an organic charge-transfer compound, dimethyltetrathiafulvalene (DMTTF)-dibromodichloro-p-benzoquinone (2,6QBr(2)Cl(2)), which is a neutral compound located near the neutral-ionic phase boundary and shows quantum paraelectricity at low temperatures. By an irradiation of a femtosecond laser pulse, an ionic domain consisting of ~40 molecules is introduced into the neutral lattice per photon, giving rise to coherent molecular oscillations with fractional charge modulations over ~400 molecules. This response is due to the recovery of ferroelectric nature from the quantum paraelectricity by a photoinjection of an ionic domain with a large dipole moment.
Department of Advanced Materials Science, University of Tokyo, Kashiwa, Chiba 277-8561, Japan.
Tatsuya
T
Miyamoto
Kazuki
K
Kimura
Takanori
T
Hamamoto
Hirotaka
H
Uemura
Hiroyuki
H
Yada
Hiroyuki
H
Matsuzaki
Sachio
S
Horiuchi
Hiroshi
H
Okamoto
D016227:Benzoquinones / Q000737:chemistry*; D006571:Heterocyclic Compounds / Q000737:chemistry*; D007834:Lasers; D044367:Phase Transition / Q000528:radiation effects; D055668:Photochemical Processes; D011789:Quantum Theory; D013059:Spectrum Analysis, Raman
D016227:Benzoquinones; D006571:Heterocyclic Compounds; C063887:tetrathiafulvalene