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Numéro
J. Phys. IV France
Volume 131, December 2005
Page(s) 111 - 114
DOI https://doi.org/10.1051/jp4:2005131024
Publié en ligne 18 janvier 2006
International Workshop on Electronic Crystals
S. Brazovskii, P. Monceau and N. Kirova
J. Phys. IV France 131 (2005) 111-114
DOI: 10.1051/jp4:2005131024

Depinning of the Spin-Density Wave in (TMTTF)2Br under pressure

K. Nomura1, K. Ishimura1, K. Fujimoto1, N. Matsunaga1, T. Nakamura2, T. Takahashi3 and G. Saito4

1  Division of Physics, Hokkaido University, Sapporo, Japan
2  Institute for Molecular Science, Okazaki, Japan
3  Department of Physics, Gakushuin University, Tokyo, Japan
4  Division of Chemistry, Kyoto University, Kyoto, Japan


Abstract
We have investigated the sliding motion of the SDW in the organic compound (TMTTF)2Br under the pressure with the measurement of the non-linear conductivity. Below the SDW transition temperature $T_{\rm SDW}$, we observed the sharp increase of conductivity with the clear threshold electric field $E_{\rm T}$, associated with the depinning of the SDW. For the typical sample, the temperature dependence of $E_{\rm T}$ shows a peak around 0.3 $T_{\rm SDW}$ in each pressure. In addition, the field hysteresis with the switching appears in the dc I-V characteristics around 0.3 $T_{\rm SDW}$. The excess conductivity, dominated by the kinetic friction, shows a sharp increase below 0.3 $T_{\rm SDW}$. These behaviors indicate that the sliding mechanism of SDW varies across 0.3 $T_{\rm SDW}$, which is almost equal to the sub-phase transition temperature. This fact suggests that the transition at 0.3 $T_{\rm SDW}$ is associated with both the magnetic and charge degrees of freedom.



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