Direkt zum Inhalt

Schliemann, John

Disorder-induced noncollinear ferromagnetism in models for (III,Mn)V semiconductors

Schliemann, John (2003) Disorder-induced noncollinear ferromagnetism in models for (III,Mn)V semiconductors. Phys. Rev. B 67, 045202.

Veröffentlichungsdatum dieses Volltextes: 22 Mai 2013 13:50
Artikel
DOI zum Zitieren dieses Dokuments: 10.5283/epub.28240


Zusammenfassung

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.



Beteiligte Einrichtungen


Details

DokumentenartArtikel
Titel eines Journals oder einer ZeitschriftPhys. Rev. B
Verlag:American Physical Society
Band:67
Seitenbereich:045202
Datum24 Januar 2003
InstitutionenPhysik > Institut für Theoretische Physik > Lehrstuhl Professor Grifoni > Arbeitsgruppe John Schliemann
Identifikationsnummer
WertTyp
10.1103/PhysRevB.67.045202DOI
Dewey-Dezimal-Klassifikation500 Naturwissenschaften und Mathematik > 530 Physik
StatusVeröffentlicht
BegutachtetJa, diese Version wurde begutachtet
An der Universität Regensburg entstandenNein
URN der UB Regensburgurn:nbn:de:bvb:355-epub-282405
Dokumenten-ID28240

Bibliographische Daten exportieren

Nur für Besitzer und Autoren: Kontrollseite des Eintrags

nach oben