Eur. Phys. J. B 67, 513-517 (2009)
https://doi.org/10.1140/epjb/e2009-00062-2

Charge dynamics of the spin-density-wave state in BaFe₂As₂

¹ Laboratorium für Festkörperphysik, ETH - Zürich, 8093 Zürich, Switzerland
² Geballe Laboratory for Advanced Materials and Department of Applied Physics, Stanford University, Stanford, 94305-4045 California, USA

Corresponding author: ^a degiorgi@solid.phys.ethz.ch

Received: 28 November 2008
Revised: 19 January 2009
Published online: 21 February 2009

Abstract

We report on a thorough optical investigation of BaFe₂As₂ over a broad spectral range and as a function of temperature, focusing our attention on its spin-density-wave (SDW) phase transition at T_SDW = 135 K. While BaFe₂As₂ remains metallic at all temperatures, we observe a depletion in the far infrared energy interval of the optical conductivity below T_SDW, ascribed to the formation of a pseudogap-like feature in the excitation spectrum. This is accompanied by the narrowing of the Drude term consistent with the dc transport results and suggestive of suppression of scattering channels in the SDW state. About 20% of the spectral weight in the far infrared energy interval is affected by the SDW phase transition.