Strong correlation and massive spectral-weight redistribution induced spin density wave in a-Fe1.06Te

TL;DR

This study reveals how a strong spin density wave forms in a-Fe1.06Te due to significant spectral-weight redistribution and correlation effects, leading to a transition from incoherent to coherent electronic states.

Contribution

It provides detailed ARPES evidence of spectral-weight transfer and the formation of a spin density wave in a-Fe1.06Te, highlighting the role of strong correlations.

Findings

Massive spectral-weight transfer over a large energy range

Emergence of coherent quasiparticles in the magnetic state

Distinct behavior compared to other iron-based systems

Abstract

The electronic structure of a-Fe1.06Te is studied with angle-resolved photoemission spectroscopy. We show that there is substantial spectral weight around Gamma and X, and lineshapes are intrinsically incoherent in the paramagnetic state. The magnetic transition is characterized by a massive spectral-weight transfer over an energy range as large as the band width, which even exhibits a hysteresis loop that marks the strong first order transition. Coherent quasiparticles emerge in the magnetically ordered state due to decreased spin fluctuations, which account for the change of transport properties from insulating behavior to metallic behavior. Our observation demonstrates that Fe1.06Te distinguishes itself from other iron-based systems with more local characters and much stronger interactions among different degrees of freedom, and how a spin density wave is formed in the presence of strong correlation.