Spiral charge frustration in molecular conductor (DI-DCNQI)2Ag

TL;DR

This paper theoretically investigates spiral charge frustration in a quasi-one-dimensional molecular conductor, revealing how it leads to complex charge-lattice order and temperature-dependent molecular displacements, aligning with recent experimental findings.

Contribution

It introduces a theoretical framework explaining spiral charge frustration effects and self-organization in (DI-DCNQI)2Ag, connecting charge, lattice interactions, and experimental observations.

Findings

Relief of spiral charge frustration leads to complex charge-lattice order.

A characteristic temperature causes a sudden increase in molecular displacements.

Results reconcile experimental data with theoretical models.

Abstract

We theoretically study the effect of spiral-type charge frustration in a quasi-one-dimensional molecular conductor (DI-DCNQI)2Ag. We clarify how the spiral frustration in the interchain Coulomb repulsion is relieved and leads to a self-organization of complex charge-lattice ordered chains, in agreement with the recent synchrotron X-ray study [T. Kakiuchi et al., Phys. Rev. Lett. 98, 066402 (2007)]. In addition, we find that a keen competition between charge and lattice degrees of freedom under the frustration gives rise to a characteristic temperature within the ordered phase, below which a drastic growth of molecular displacements occurs. Our results enlighten the relevance of the spiral frustration and provide a possible reconciliation among puzzling experimental data.