Dimerization-Induced Fermi-Surface Reconstruction in IrTe2

TL;DR

This study investigates how dimer formations in IrTe2 cause complex Fermi surface reconstructions, revealing a quasi-two-dimensional conducting plane and the role of local instabilities in phase transitions.

Contribution

It provides experimental evidence linking dimerization patterns to Fermi surface changes and identifies the driving forces behind complex dimer formations in IrTe2.

Findings

Fermi surface reconstruction linked to 1/5- and 1/8-type dimerizations

Discovery of a quasi-two-dimensional conducting plane induced by dimerization

Phase transition to higher dimer density driven by local instabilities

Abstract

We report a de Haas-van Alphen (dHvA) oscillation study on IrTe2 single crystals showing complex dimer formations. By comparing the angle dependence of dHvA oscillations with band structure calculations, we show distinct Fermi surface reconstruction induced by a 1/5-type and a 1/8-type dimerizations. This verifies that an intriguing quasi-two-dimensional conducting plane across the layers is induced by dimerization in both cases. A phase transition to the 1/8 phase with higher dimer density reveals that local instabilities associated with intra- and interdimer couplings are the main driving force for complex dimer formations in IrTe2.