Interlayer exchange in (Ga,Mn)As/(Al,Ga)As/(Ga,Mn)As semiconducting ferromagnet/nonmagnet/ferromagnet trilayer structures

During recent years diluted magnetic semiconductors based on III-V compounds have been of considerable interest. In this respect we review the basic properties of these materials, which are nearly exclusively Mn-based systems, such as GaMnAs, InMnAs, GaMnSb, and GaN:Mn. We discuss the nature of Mn impurity. Different Mn centers are considered and experimental pieces of evidence suggesting the dominating role of Mn (d5 ) configuration are given. Then we analyze s, p -d exchange, together with resulting magnetooptical properties (in particular absorption edge slitting for heavily p-type GaMnAs). The coupling between Mn ions (d-d exchange) and ferromagnetic ordering observed in InMnAs and GaMnAs is the next subject. Some mechanisms responsible for this ordering are presented. Finally we discuss transport properties and some selected problems of quantum structures based on III-V diluted magnetic semiconductors.

Section: Other Issuesmentioning

confidence: 99%

“…The coupling between magnetic GaMnAs layers was investigated for a series of trilayer system, consisting of GaMnAs layers separated by nonmagnetic GaAlAs layer [81]. The experiments were performed as a function of nonmagnetic layer thickness, to study the distance dependence of the coupling.…”

Section: Other Issuesmentioning

confidence: 99%

Diluted Magnetic III-V Semiconductors

Twardowski

2000

“…In contrast, in the (Ga,Mn)As-based semiconductor ferromagnetic/ nonmagnetic systems interlayer coupling of opposite FM sign was observedby magnetic measurements [13][14][15], neutron diffraction [16], and polarized neutron reflectometry [17]. These structures differ from the previously considered EuS-based ferromagnetic semiconductor multilayers by many aspects, which all can affect the IEC.…”

Section: Interlayer Coupling and The Tight-binding Modelmentioning

confidence: 61%

“…This so-called tunnel anisotropic magnetoresistance (TAMR) effect was observed when the saturation magnetization direction was changed in-plane [9][10][11] as well as when it was turned perpendicular to the magnetic layer [11,12]. It was also shown that the magnetization vectors of consecutive (Ga,Mn)As ferromagnetic layers separated by nonmagnetic spacers in a multilayer structure are correlated by an interlayer coupling [13][14][15][16][17] and structures exhibiting giant magnetoresistance (GMR) were obtained [14].…”

Section: Introductionmentioning

confidence: 89%

Spin-Dependent Phenomena in (Ga,Mn)As Heterostructures

Sankowski

Kacman

2006

A model for spin-dependent tunneling in semiconductor heterostructures, which combines a multi-orbital empirical tight-binding approach with a Landauer-Büttiker formalism, is presented. Using this approach we explain several phenomena observed in modulated structures of (Ga,Mn)As, i.e., large values of the electron current spin polarization in magnetic EsakiZener diode and the high tunneling magnetoresistance ratio. Next, the relevance of this theory to assess the tunneling anisotropic magnetoresistance effect is studied. The results of applying the tight-binding model to describe the recently observed interlayer exchange coupling in (Ga,Mn)As-based superlattices are also shown.

“…In the latter case one should use asymmetric trilayer structures (see Fig. 1b) to allow for the clear distinction between the non-coupled layers due to their different coercive fields (the method used, e.g., in the studies of GaMnAs-AlGaAs trilayers [33]). …”

Section: Interlayer Exchange In Ferromagnetic Semiconductor Superlattmentioning

confidence: 99%

Semiconductor Ferromagnetic Structures

Story

2000

Ferromagnetic semiconductor structures such as superlattices or trilayers form a new class of magnetic systems composed entirely of semiconductor materials. The examples are Ga 1-x Mnx As-AlGaAs with the ferromagnetic layer of GaMnAs semimagnetic (diluted magnetic) semiconductor or EuS-PbS with the ferromagnetic member (EuS) of the family of europium chalcogenides. We discuss the spectrum of perspective ferromagnetic semiconductor materials, the effect of size and stress on magnetic properties of ultrathin semiconductor ferromagnetic layers, and the effect of interlayer exchange in all-semiconductor systems.