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Title: What is the valence of Mn in Ga1-xMnxN?

Motivated by the potential high Curie temperature of Ga1-xMnxN, we investigate the controversial Mn valence in this diluted magnetic semiconductor. From a first-principles Wannier-function analysis of the high energy Hilbert space, we find unambiguously the Mn valence to be close to 2+(d5), but in a mixed spin configuration with average magnetic moments of 4µB. By integrating out high-energy degrees of freedom differently, we further demonstrate the feasibility of both effective d4 and d5 descriptions. These two descriptions offer simple pictures for local and extended properties of the system, and highlight the dual nature of its doped hole. Specifically, in the effective d5 description, we demonstrate novel physical effects absent in previous studies. Thus, our derivation highlights the richness of low-energy sectors in interacting many-body systems and the generic need for multiple effective descriptions.
Authors:
 [1] ;  [2] ;  [2] ;  [3] ;  [2]
  1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  2. Louisiana State Univ., Baton Rouge, LA (United States)
  3. Brookhaven National Lab. (BNL), Upton, NY (United States); State Univ. of New York, Stony Brook, NY (United States)
Publication Date:
OSTI Identifier:
1225424
Grant/Contract Number:
AC05-00OR22725
Type:
Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 115; Journal Issue: 19; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Research Org:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY