| Issue |
J. Phys. IV France
Volume 09, Number PR10, December 1999
International Workshop on Electronic CrystalsECRYS-99 |
|
|---|---|---|
| Page(s) | Pr10-351 - Pr10-351 | |
| DOI | https://doi.org/10.1051/jp4:19991093 | |
ECRYS-99
J. Phys. IV France 09 (1999) Pr10-351-Pr10-351
DOI: 10.1051/jp4:19991093
The dimensionality-driven metal-insulator transition in organic Bechgaard salts
V. Vescoli1, L. Degiorgi1, W. Henderson2, G. Gruner2 and L.K. Montgomery31 Laboratorium für Festkorperphysik, ETH-Zurich, 8093 Zurich, Switzerland
2 Department of Physics, UCLA, Los Angeles, CA 90095-1547, U.S.A.
3 Department of Chemistry, Indiana University, Bloomington, IN 47405, U.S.A.
Abstract
Optical experiments were conducted on a series of organic linear chain conductors (i.e.,
(TMTTF)2X with X=PF6 and Br, and (TMTSF)2X with X=ClO4, PF6, AsF6) with different
values of the interchain single electron transfer integral tb, which quantifies the degree of
anisotropy. We have investigated the dynamics of the charge excitation spectrum in the
frequency range from 1 to 105 cm-1. Electron-electron interactions together with Umklapp
scattering resulted in a correlation gap and an insulating state for small tb. An insulator-tometal
transition was observed when tb exceeded a critical value, on the order of the
correlation gap. This optical work shows that an insulator (TMTTF) to metal (TMTSF)
transition can be associated with electron deconfinement. Moreover, by contrasting optical
with magnetic properties we found indications which are suggestive of metal with spin-charge
separation
[l] V. Vescoli et al., Science 281, 1181 (1998)
© EDP Sciences 1999