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Disorder-induced noncollinear ferromagnetism in models for (III,Mn)V semiconductors
Article
Schliemann, John (2003) Disorder-induced noncollinear ferromagnetism in models for (III,Mn)V semiconductors. Phys. Rev. B 67, 045202.DOI to cite this document: 10.5283/epub.28240
Abstract
We study the ground-state properties of kinetic-exchange models for (III,Mn)V semiconductors with randomly distributed Mn ions. Our method is embedded in a path integral spin-wave-type formalism leading to an effective action for Mn spins only with full Matsubara frequency dependence. The zero-frequency contribution to this action is equivalent to static perturbation theory and characterizes the ...
We study the ground-state properties of kinetic-exchange models for (III,Mn)V semiconductors with randomly distributed Mn ions. Our method is embedded in a path integral spin-wave-type formalism leading to an effective action for Mn spins only with full Matsubara frequency dependence. The zero-frequency contribution to this action is equivalent to static perturbation theory and characterizes the stability of a given spin configuration, while the component linear in frequency can be interpreted as the joint Berry phase of the Mn and carrier system. For simple parabolic-band carriers the collinear ferromagnetic state with all Mn spins in parallel is always stationary but generically unstable. This instability can be characterized in terms of inverse participation ratios and is due to long-ranged nonlocal spin fluctuations. We also present results for the ground-state magnetization as a function of an external field. For carrier dispersions involving anisotropy induced by spin-orbit coupling the collinear state is not even stationary and therefore also not the ground state. This interplay between the anisotropy in the carrier system and the disorder in the Mn positions reflects recent findings by Zarand and Janko [Phys. Rev. Lett. 89, 047201 (2002)] obtained within the RKKY approximation. The stationarity of the collinear state (with the magnetization pointing in one of the cubic symmetry directions) is restored in the continuum or virtual crystal approximation where disorder is neglected.
Involved Institutions
Details
| Item type | Article | ||||
| Journal or Publication Title | Phys. Rev. B | ||||
| Publisher | American Physical Society | ||||
| Volume | 67 | ||||
| Page Range | 045202 | ||||
| Date | 24 January 2003 | ||||
| Date of publication | 22 May 2013 13:50 | ||||
| Institutions | Physics > Institute of Theroretical Physics > Chair Professor Grifoni > Group John Schliemann | ||||
| Identification Number |
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| Dewey Decimal Classification | 500 Science > 530 Physics | ||||
| Status | Published | ||||
| Refereed | Yes, this version has been refereed | ||||
| Created at the University of Regensburg | No | ||||
| URN of the UB Regensburg | urn:nbn:de:bvb:355-epub-282405 | ||||
| Item ID | 28240 |
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