1203.4061 (A. F. Fang et al.)

Kinetic energy reduction driven structural phase transition in IrTe$_2$:
A combined study of optical spectroscopy and band structure calculations    [PDF]

A. F. Fang, G. Xu, T. Dong, P. Zheng, N. L. Wang

IrTe$_2$ exhibits an interesting interplay between superconductivity and a structural phase transition at 280 K. Understanding this structural transition is a crucial step towards understanding the electronic properties of the material. We present a combined optical spectroscopy and band structure calculation study on the compound across the transition. The study reveals that IrTe$_2$ is a good metal with a rather high plasma frequency. The phase transition leads to a reconstruction of band structure and significant reduction of the conducting carriers. We elaborate that the transition is not driven by the density wave type instability but caused by the crystal field effect which further splits/separates the energy levels of Te (p$_x$, p$_y$) and Te p$_z$ bands. The kinetic energy of the electrons is reduced due to an increased occupation of the further lowered Te (p$_x$, p$_y$) energy levels.

View original: http://arxiv.org/abs/1203.4061