Center for Artificial Low Dimensional Electronic Systems

Pressure and Magnetic-Field-Induced Small 2D Fermi Surface in the Quasi-1D CDW-Organic Conductor, HMTSF-TCNQ

Keizo Murata

September 22(Thu) - September 22(Thu), 2016

 It has been known that the organic quasi-one-dimensional (Q1D) metallic conductor (TMTSF)­2X (tetramethyltetraselenafulvalene and X:anion) shows a spin density wave (SDW)  state (below 12 K), superconductivity (below 1.5 K) and field-induced (FI) small 2D Fermi-surface pocket in a specific domain of temperature, pressure and magnetic field. The FISDW state accompanies a quantum Hall effect (QHE).

 It is of great interest whether or not the similar effect of generating a small 2D Fermi surface by managing pressure and magnetic field in the Q1D charge density wave (CDW) system similarly to those SDW system. We studied HMTSF-TCNQ (hexamethylenetetraselenafulvalene- tetracyanoquinodimethane), a typical CDW system, by examining the magnetoresistance, angular dependence magnetoresistance oscillation and Hall resistance, using miniature piston cylinder pressure cell and high magnetic field (~31 T) and low temperature (down to 0.4 K), and found QHE behavior in a specific pressure region (0.8 – 1.2 GPa) where CDW is partially suppressed.

Keywords:

Magnetic-Field-Induced State, Quantum Hall Effect, Small 2D Fermi Surface, CDW

[1] MURATA, K., FUKUMOTO, Y., YOKOGAWA, K.,  KANG, W., TAKAOKA, R., TADA, R., HIRAYAMA, H., BROOKS, J.S., GRAF, D.. YOSHINO, H., SASAKI, T., KATO, R., 2014, Magnetic-Field-Induced Phase Transition and a Possible Quantum Hall Effect in the Quasi-One-Dimensional CDW Organic Conductor HMTSF-TCNQ,  J. Modern Physics, 5, 673-679.