23 May

Recent advances in electron/spin-lattice coupling in low dimensional organic conductors

Thursday 23 May 2019, 03:00pm

ICN2 Seminar Hall, ICN2 Building, UAB

By Dr Jean Paul Pouget,  Laboratoire de Physique des Solides, CNRS UMR 8502, Université de Paris-Sud, Université Paris-Saclay, Orsay, France

Abstract: We survey some recent findings in the physics and chemistry of low dimensional organic conductors. We emphasize particularly the crucial role of anion (X) - donor (D) interaction in achieving charge localization phenomena observed in several families of quarter-filled D2X salts [1].

We also show that ordering effects involving several types of structural degrees of freedom such as anion orientation or ethylene conformation subtly controls the electronic phase diagram of these systems. Among recent finding we show that unexpectedly some of 2D (BEDT-TTF)2X metals exhibit in fact a hidden 1D electronic dimension whose incipient 2kF or 4kF charge density wave instability drives the electronic ground state.

In the charge localized regime, AF coupled spin degrees of freedom strongly interact with the lattice which drives a spin-Peierls transition at TSP. We present here, for the Fabre salt (TMTTF)2PF6, the first neutron scattering investigation of magneto-structural excitations of the spin-Peierls instability above and below TSP [2].

Hosted by: Prof. Pablo Ordejón, Theory and Simulation Group Leader at ICN2