Hopping dynamics of interacting polarons

S. Ciuchi (1) , Simone Fratini (2)

1 Dipartimento di Fisica [L'Aquila]
2 NEEL - TMC - Théorie de la Matière Condensée

We derive an effective cluster model to address the transport properties of mutually interacting small polarons. We propose a decoupling scheme where the hopping dynamics of any given particle is determined by separating out explicitly the degrees of freedom of its environment, which are treated as a statistical bath. The general cavity method developed here shows that the long-range Coulomb repulsion between the carriers leads to a net increase in the thermal activation barrier for electrical transport and hence to a sizable reduction in the carrier mobility. A mean-field calculation of this effect is provided based on the known correlation functions of the interacting liquid in two and three dimensions. The present theory gives a natural explanation of recent experiments performed in organic field-effect transistors with highly polarizable gate dielectrics and might well find application in other classes of polaronic systems such as doped transition-metal oxides.

Domaines: Electrons fortement corrélés [cond-mat.str-el]

S. Ciuchi, Simone Fratini. Hopping dynamics of interacting polarons. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2009, 79, pp.035113. ⟨10.1103/PhysRevB.79.035113⟩. ⟨hal-00704617⟩