2010/06/20 by Á. Antal, Ágnes Antal, Titusz Fehér +9
Materials Science · Physics and Astronomy · #Magnetism in coordination complexes #Organic and Molecular Conductors Research #Quantum and electron transport phenomena #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.84.075124
published as Phys. Rev. B 84, 075124 (2011) · 18 pages, 11 figures
arxiv created 2010/06/20 · openalex publication_date 2011/08/08 · arxiv updated 2013/09/24 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
A high frequency (111.2--420 GHz) electron spin resonance study of the interlayer spin diffusion is presented in the conducting phases of the layered organic compounds, \ensuremathκ-(BEDT-TTF)2Cu[N(CN)2]X (\ensuremathκ-ET2-X), X=Cl or Br. The interlayer spin cross relaxation time Tx and the intrinsic spin relaxation time T2 of single layers are measured as a function of temperature and pressure. Spin diffusion is two dimensional in the high temperature bad-metal phase (i.e., electrons are confined to a single molecular layer for longer than T2). The interlayer electron hopping frequency \ensuremathν_\ensuremath⊥=1/(2Tx) decreases along the bad-metal to Mott insulator crossover and increases along the bad-metal to normal metal (or superconductor) crossover. The density of states (DOS) is determined from a comparison of Tx and the interlayer resistivity. In the bad-metal phase it is four to five times larger than the DOS calculated from the electronic structure neglecting electron correlations. In \ensuremathκ-ET2-X the DOS increases with pressure along the bad-metal to normal metal crossover. Results are compared with predictions of the dynamical mean field theory.