Light-induced ferromagnetism in III-V-based diluted magnetic semiconductor heterostructures

Munekata, H.; Abe, Takahiro; Koshihara, Shin‐ya; Oiwa, A.; Hirasawa, Masahiro; Katsumoto, Shingo; Iye, Yasuhiro; Urano, Chiharu; Takagi, H.

doi:10.1063/1.364889

Cited by 81 publications

(46 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Prospects for new technologies, based, for example, on materials in which the ferromagnetic transition can be controlled by light or on ͑III,Mn͒V Faraday isolators monolithically integrated with existing semiconductor lasers, have motivated research in magneto-optical properties of DMSs ͑Koshihara et al, 1997;Munekata et al, 1997;Sugano and Kojima, 2000;Matsukura et al, 2002͒. Apart from these applied physics interests, ac probes have been used to study DMS materials with a wide range of experimental techniques. In Secs.…”

Section: Magneto-opticsmentioning

confidence: 99%

Theory of ferromagnetic (III,Mn)V semiconductors

et al. 2006

View full text Add to dashboard Cite

The body of research on ͑III,Mn͒V diluted magnetic semiconductors ͑DMSs͒ initiated during the 1990s has concentrated on three major fronts: ͑i͒ the microscopic origins and fundamental physics of the ferromagnetism that occurs in these systems, ͑ii͒ the materials science of growth and defects, and ͑iii͒ the development of spintronic devices with new functionalities. This article reviews the current status of the field, concentrating on the first two, more mature research directions. From the fundamental point of view, ͑Ga,Mn͒As and several other ͑III,Mn͒V DMSs are now regarded as textbook examples of a rare class of robust ferromagnets with dilute magnetic moments coupled by delocalized charge carriers. Both local moments and itinerant holes are provided by Mn, which makes the systems particularly favorable for realizing this unusual ordered state. Advances in growth and postgrowth-treatment techniques have played a central role in the field, often pushing the limits of dilute Mn-moment densities and the uniformity and purity of materials far beyond those allowed by equilibrium thermodynamics. In ͑III,Mn͒V compounds, material quality and magnetic properties are intimately connected. This review focuses on the theoretical understanding of the origins of ferromagnetism and basic structural, magnetic, magnetotransport, and magneto-optical characteristics of simple ͑III,Mn͒V epilayers, with the main emphasis on ͑Ga,Mn͒As. Conclusions are arrived at based on an extensive literature covering results of complementary ab initio and effective Hamiltonian computational techniques, and on comparisons between theory and experiment. The applicability of ferromagnetic semiconductors in microelectronic technologies requires increasing Curie temperatures from the current record of 173 K in ͑Ga,Mn͒As epilayers to above room temperature. The issue of whether or not this is a realistic expectation for ͑III,Mn͒V DMSs is a central question in the field and motivates many of the analyses presented in this review.

show abstract

Section: Magneto-opticsmentioning

confidence: 99%

Theory of ferromagnetic (III,Mn)V semiconductors

et al. 2006

View full text Add to dashboard Cite

show abstract

“…The lattice GaMnAs samples were grown in a MBE system constant aLTGaAs taken from Eq. (1) corresponds to a (KRYOVAK) equipped with an As 2 valve cracker concentration of As antisites equal to 3 X 1019 cm- 3 .…”

Section: "1~mentioning

confidence: 99%

“…On the one hand, recent theoretical modelling [1][2][3][4][5] and GaMnAs [6][7][8][9][10][11] have been gaining an of magnetism in GaMnAs quantum well structures [191, increasing interest in recent years due to the expanding based on Monte Carlo simulations on a confinementresearch activity in the field of spintronics [12], where adapted RKKY exchange interaction model, predicts a the possibility of integrating spin-dependent effects into lower limit for the GaMnAs thickness of 9 ML (25 A) the electronic devices seems to be very attractive. In for the ferromagnetic phase to occur.…”

Section: Introductionmentioning

confidence: 99%

Ferromagnetic GaMnAs/GaAs superlattices—MBE growth and magnetic properties

et al. 2002

View full text Add to dashboard Cite

“…In fact, a negative sign of the R yx has been observed in films of (In,Mn)As [12,13], (In,Mn)Sb [15,16], and (Ga,Mn)Sb [17], where the bulk asymmetry is expected to be much stronger. However, the striking behavior of R yx (T ), including the change of sign revealed here, has not been anticipated theoretically [4,5].…”

mentioning

confidence: 99%

Anomalous Hall Effect in Field-Effect Structures of (Ga,Mn)As

et al. 2010

View full text Add to dashboard Cite

The anomalous Hall effect in metal-insulator-semiconductor structures having thin (Ga,Mn)As layers as a channel has been studied in a wide range of Mn and hole densities changed by the gate electric field. Strong and unanticipated temperature dependence, including a change of sign, of the anomalous Hall conductance σxy has been found in samples with the highest Curie temperatures. For more disordered channels, the scaling relation between σxy and σxx, similar to the one observed previously for thicker samples, is recovered.PACS numbers: 72.25. Dc, 73.40.Qv, 75.50.Pp, Along with anisotropic magnetoresistance, the anomalous Hall effect (AHE) results from an interplay between spin-orbit interactions and spin polarization of electric current specific to ferromagnets. It has been recently realized that for a certain region of conductivities, the anomalous Hall conductivity σ xy is a measure of the Berry phase of carrier trajectories in the k space and, thus, provides information on the hitherto inaccessible aspects of the band structure topology in the presence of various spin-orbit interactions [1,2,3,4,5]. Interestingly, the effect appears to be qualitatively immune to disorder, except for the case of linear-in-k Rashba-type Hamiltonians in two-dimensional electron systems, where the contribution to σ xy vanishes [6] unless the lifetime is spin-dependent [7]. Furthermore, a surprisingly universal empirical scaling relation between the Hall and longitudinal conductivities, σ xy ∼ σ γ xx , γ ≈ 1.6 has been found to be obeyed by a number of materials on the lower side of their conductivity values [8], where Anderson-Mott quantum localization effects should be important.In this Letter, we report on Hall resistance studies as a function of temperature and gate electric field carried out for metal-insulator-semiconductor (MIS) structures containing a thin conducting channel of ferromagnetic (Ga,Mn)As. We find out that in the σ xx range up to 10 2 S/cm, σ xy obeys a scaling relation with a similar value of the exponent γ. However, for σ xx > ∼ 10 2 S/cm the scaling relation breaks down entirely. Surprisingly, in this regime and below the Curie temperature T C , σ xy tends to decrease rather abruptly with decreasing temperature, and even reverses its sign in some cases, in the region where neither resistance R nor magnetization M vary significantly with temperature. The effect has not been observed in thicker films and appears to have no explanation within the existing theory, pointing to the importance of yet unrevealed confinement effects.The studied thin layers of tensile-strained (Ga,Mn)As have been deposited by low-temperature molecular beam epitaxy onto a buffer layer consisting of 4-nm GaAs/ 30-nm Al 0.75 Ga 0.25 As/ 500-nm In 0.15 Ga 0.85 As/30-nm GaAs grown on a semi-insulating GaAs (001) substrate. Upon growth, Hall bars having a channel of 30 or 40-µm width and ∼200-µm length are patterned by photolithography and wet etching. Subsequently, samples are annealed at 180• C for 5 min or introduced directly into an a...

show abstract

Light-induced ferromagnetism in III-V-based diluted magnetic semiconductor heterostructures

Cited by 81 publications

References 9 publications

Theory of ferromagnetic (III,Mn)V semiconductors

Theory of ferromagnetic (III,Mn)V semiconductors

Ferromagnetic GaMnAs/GaAs superlattices—MBE growth and magnetic properties

Anomalous Hall Effect in Field-Effect Structures of (Ga,Mn)As

Contact Info

Product

Resources

About