Competing SDW Phases and Quantum Oscillations in (TMTSF)2ClO4 in Magnetic Field

TL;DR

This paper introduces a new theoretical approach to study spin density waves in (TMTSF)2ClO4, accounting for lattice dimerization and magnetic breakdown, successfully explaining experimental quantum oscillation data.

Contribution

It develops a matrix formulation for SDW response considering hybridization and provides an exact treatment of magnetic breakdown in a dimerized lattice.

Findings

Results match experimental quantum oscillation data.

Fitted anion potential consistent with interchain hopping.

Explains rapid 260T oscillations and Tc dependence on magnetic field.

Abstract

We propose a new approach for studying spin density waves (SDW) in the Bechgaard salt (TMTSF)2ClO4 where lattice is dimerized in transverse direction due to anion ordering. The SDW response is calculated in the matrix formulation that rigorously treats the hybridization of inter-band and intra-band SDW correlations. Since the dimerization gap is large, of the order of transverse bandwidth, we also develop an exact treatment of magnetic breakdown in the external magnetic field. The obtained results agree with the experimental data on the fast magneto-resistance oscillations. Experimentally found 260T rapid oscillations and the characteristic Tc dependance on magnetic field of relaxed material are fitted with our results for anion potential of the order of interchain hopping.