2006/03/31 by Kenneth S. Burch, K. S. Burch, David Shrekenhamer +12 · 1 citation
Materials Science · Physics and Astronomy · #Electronic and Structural Properties of Oxides #Magnetic and transport properties of perovskites and related materials #ZnO doping and properties #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.97.087208
published as Phys. Rev. Lett. 97, 087208 (2006) · 4 pages, 4 figures
arxiv created 2006/07/21 · openalex publication_date 2006/08/23 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The band structure of a prototypical dilute magnetic semiconductor (DMS), Ga_1\ensuremath-xMnxAs, is studied across the phase diagram via infrared and optical spectroscopy. We prove that the Fermi energy (EF) resides in a Mn-induced impurity band (IB). Specifically the changes in the frequency dependent optical conductivity [\ensuremathσ1(\ensuremathω)] with carrier density are only consistent with EF lying in an IB. Furthermore, the large effective mass (m*) of the carriers inferred from our analysis of \ensuremathσ1(\ensuremathω) supports this conclusion. Our findings demonstrate that the metal to insulator transition in this DMS is qualitatively different from other III-V semiconductors doped with nonmagnetic impurities. We also provide insights into the anomalous transport properties of Ga_1\ensuremath-xMnxAs.