Cubic anisotropy in (Ga,Mn)As layers : Experiment and theory
(2018) In Physical Review B 97(18).- Abstract
Historically, comprehensive studies of dilute ferromagnetic semiconductors, e.g., p-type (Cd,Mn)Te and (Ga,Mn)As, paved the way for a quantitative theoretical description of effects associated with spin-orbit interactions in solids, such as crystalline magnetic anisotropy. In particular, the theory was successful in explaining uniaxial magnetic anisotropies associated with biaxial strain and nonrandom formation of magnetic dimers in epitaxial (Ga,Mn)As layers. However, the situation appears much less settled in the case of the cubic term: the theory predicts switchings of the easy axis between in-plane (100) and (110) directions as a function of the hole concentration, whereas only the (100) orientation has been found experimentally.... (More)
Historically, comprehensive studies of dilute ferromagnetic semiconductors, e.g., p-type (Cd,Mn)Te and (Ga,Mn)As, paved the way for a quantitative theoretical description of effects associated with spin-orbit interactions in solids, such as crystalline magnetic anisotropy. In particular, the theory was successful in explaining uniaxial magnetic anisotropies associated with biaxial strain and nonrandom formation of magnetic dimers in epitaxial (Ga,Mn)As layers. However, the situation appears much less settled in the case of the cubic term: the theory predicts switchings of the easy axis between in-plane (100) and (110) directions as a function of the hole concentration, whereas only the (100) orientation has been found experimentally. Here, we report on the observation of such switchings by magnetization and ferromagnetic resonance studies on a series of high-crystalline quality (Ga,Mn)As films. We describe our findings by the mean-field p-d Zener model augmented with three new ingredients. The first one is a scattering broadening of the hole density of states, which reduces significantly the amplitude of the alternating carrier-induced contribution. This opens the way for the two other ingredients, namely the so-far disregarded single-ion magnetic anisotropy and disorder-driven nonuniformities of the carrier density, both favoring the (100) direction of the apparent easy axis. However, according to our results, when the disorder gets reduced, a switching to the (110) orientation is possible in a certain temperature and hole concentration range.
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- author
- Sawicki, Maciej ; Proselkov, O. ; Sliwa, C. ; Aleshkevych, P. ; Domagala, J. Z. ; Sadowski, J. LU and Dietl, T.
- organization
- publishing date
- 2018-05-03
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Physical Review B
- volume
- 97
- issue
- 18
- article number
- 184403
- publisher
- American Physical Society
- external identifiers
-
- scopus:85047133231
- ISSN
- 2469-9950
- DOI
- 10.1103/PhysRevB.97.184403
- language
- English
- LU publication?
- yes
- additional info
- Funding Information: This study has been supported by the National Science Centre (Poland) through PRELUDIUM Grant No. UMO - 2012/05/N/ST3/03147 and MAESTRO Grant No. UMO - 2011/02/A/ST3/00125. EC Network SemiSpinNet (PITN-GA-2008-215368) contribution is also acknowledged. The International Centre for Interfacing Magnetism and Superconductivity with Topological Matter project is carried out within the International Research Agendas programme of the Foundation for Polish Science co-financed by the European Union under the European Regional Development Fund.
- id
- 4c8606a1-0284-435c-84d0-0a6b0ee8a34d
- date added to LUP
- 2022-03-31 14:44:51
- date last changed
- 2022-06-22 04:20:22
@article{4c8606a1-0284-435c-84d0-0a6b0ee8a34d,
abstract = {{<p>Historically, comprehensive studies of dilute ferromagnetic semiconductors, e.g., p-type (Cd,Mn)Te and (Ga,Mn)As, paved the way for a quantitative theoretical description of effects associated with spin-orbit interactions in solids, such as crystalline magnetic anisotropy. In particular, the theory was successful in explaining uniaxial magnetic anisotropies associated with biaxial strain and nonrandom formation of magnetic dimers in epitaxial (Ga,Mn)As layers. However, the situation appears much less settled in the case of the cubic term: the theory predicts switchings of the easy axis between in-plane (100) and (110) directions as a function of the hole concentration, whereas only the (100) orientation has been found experimentally. Here, we report on the observation of such switchings by magnetization and ferromagnetic resonance studies on a series of high-crystalline quality (Ga,Mn)As films. We describe our findings by the mean-field p-d Zener model augmented with three new ingredients. The first one is a scattering broadening of the hole density of states, which reduces significantly the amplitude of the alternating carrier-induced contribution. This opens the way for the two other ingredients, namely the so-far disregarded single-ion magnetic anisotropy and disorder-driven nonuniformities of the carrier density, both favoring the (100) direction of the apparent easy axis. However, according to our results, when the disorder gets reduced, a switching to the (110) orientation is possible in a certain temperature and hole concentration range.</p>}},
author = {{Sawicki, Maciej and Proselkov, O. and Sliwa, C. and Aleshkevych, P. and Domagala, J. Z. and Sadowski, J. and Dietl, T.}},
issn = {{2469-9950}},
language = {{eng}},
month = {{05}},
number = {{18}},
publisher = {{American Physical Society}},
series = {{Physical Review B}},
title = {{Cubic anisotropy in (Ga,Mn)As layers : Experiment and theory}},
url = {{http://dx.doi.org/10.1103/PhysRevB.97.184403}},
doi = {{10.1103/PhysRevB.97.184403}},
volume = {{97}},
year = {{2018}},
}