Structural versus electronic distortions of symmetry-broken IrTe$_2$

TL;DR

This study uses high-resolution microscopy and spectroscopy to analyze the atomic and electronic structures of IrTe2's low-temperature phase, revealing stripe superstructures and supporting an Ir dimerization mechanism over charge-density wave models.

Contribution

It provides detailed atomic and electronic structural analysis of IrTe2's low-temperature phase, emphasizing the role of Ir dimerization in the phase transition.

Findings

Confirmed stripe superstructures such as 3x, 5x, and 8x.

Observed lattice distortions consistent with recent calculations.

Identified electronic density modulations separate from structural distortions.

Abstract

We investigate atomic and electronic structures of the intriguing low temperature phase of IrTe2 using high-resolution scanning tunneling microscopy and spectroscopy. We confirm various stripe superstructures such as $\times$3, $\times$5, and $\times$8. The strong vertical and lateral distortions of the lattice for the stripe structures are observed in agreement with recent calculations. The spatial modulations of electronic density of states are clearly identified as separated from the structural distortions. These structural and spectroscopic characteristics are not consistent with the charge-density wave and soliton lattice model proposed recently. Instead, we show that the Ir (Te) dimerization together with the Ir 5d charge ordering can explain these superstructures, supporting the Ir dimerization mechanism of the phase transition.