Antiferromagnetic exchange coupling between GaMnAs layers separated by a nonmagnetic GaAs:Be spacer

Leiner, J. C.; Tivakornsasithorn, Kritsanu; Liu, X.; Furdyna, J. K.; Dobrowolska, M.; Kirby, Brian J.; Lee, H.; Yoo, Taehee; Lee, Sanghoon

doi:10.1063/1.3536669

Cited by 9 publications

(5 citation statements)

References 9 publications

(5 reference statements)

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“…In this Letter we report the observation of a striking step-wise behavior in magnetoresistance, which cannot be explained in the frame of any existing theories based only on nearest-neighbor coupling, thus providing clear evidence that next-nearest-neighbor (NNN) interactions are significant. Based on microscopic calculations, we show below that the NNN interaction is of critical importance in magnetic semiconductor multilayers, where the Fermi wavelength (~ 4 nm in our GaMnAs samples) is significantly longer than in metallic multilayers, becoming comparable to the width of the layers [12][13][14][15][16][17][18].…”

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confidence: 77%

The critical role of next-nearest-neighbor interlayer interaction in the magnetic behavior of magnetic/non-magnetic multilayers

et al. 2013

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A striking multiple-step behavior has been observed in magnetoresistance measurements during magnetization reversal in anti-ferromagnetically coupled GaMnAs/GaAs:Be multilayers. This behavior arises from the splitting of the energy degeneracy of spin configurations established by nearest-neighbor interlayer exchange coupling (NN IEC) with contribution from the next-nearestneighbor (NNN) IEC. This observation reveals that NNN IEC plays a crucial role in the magnetic behavior of these multilayer structures.

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confidence: 77%

The critical role of next-nearest-neighbor interlayer interaction in the magnetic behavior of magnetic/non-magnetic multilayers

et al. 2013

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“…This shows a clear trend: the higher the applied eld after ZFC, the lower the temperature at which the magnetization undergoes a sharp transition to larger magnitudes, which corresponds to switching of magnetization in the top from an antiparallel to a parallel magnetic alignment with respect to the magnetization of the bottom layer. We also collected data for the complimentary scenario (not shown) where, after eld cooling, there is a transition from parallel to antiparallel alignment of the two layers [24]. Fig.…”

Section: Magnetization Results Observed Onmentioning

confidence: 99%

Exchange Coupling in Magnetic Semiconductor Multilayers and Superlattices

et al. 2012

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The study of ferromagnetic semiconductors continues to be of great interest because of their potential for spintronic devices. While there has been much progress in our understanding of ferromagnetic semiconductor materials particularly of the canonical IIIV system Ga1−xMnxAs many issues still remain unresolved. One of these is the nature of interlayer exchange coupling in GaMnAs-based multilayers, an issue that is important from the point of view of possible spintronic applications. In this connection, it is important to establish under what conditions the interlayer exchange coupling between successive GaMnAs layers is antiferromagnetic or ferromagnetic, since manipulation of such interlayer exchange coupling can then be directly applied to achieve giant magnetoresistance and other devices based on this material. In this review we will describe magneto-transport, magnetization, and neutron reectometry experiments applied to two types of GaMnAs-based multilayer structures superlattices and tri-layers consisting of GaMnAs layers separated by non-magnetic GaAs spacers. These measurements serve to identify conditions under which AFM coupling will occur in such GaMnAs/GaAs multilayer systems, thus providing us the information which can be used for manipulating magnetization (and thus also giant magnetoresistance) in structures based on the ferromagnetic semiconductor GaMnAs.

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“…Measurements were performed at 30 K with current along the [1-10] direction (i.e., long dimension of the Hall device for sample series A and B) and the external field applied near the [110] crystallographic direction. The temperature of 30 K was selected in order to maximize IEC effect during the magnetization reversal process, which was dominated by crystalline anisotropy at low temperature [20][21][22][23] . The MR data are plotted in Fig.…”

Section: Observation Of Fm and Afm Interlayer Exchange Couplingmentioning

confidence: 99%

“…However, samples C3, D2, and E3 clearly show a maximum resistance at zero field during the field scans. Such recovery of the resistance maximum at zero field during field cycling is typically observed in magnetic multilayer systems with AFM IEC [20,22,23] , and represents the mechanism responsible for giant magnetoresistance (GMR). The observation of this GMR-like effect in these (Ga,Mn)As-based multilayers with different structural parameters provides additional evidence that the AFM IEC such as that discussed in the previ- ous paragraph (i.e., regarding sample B3 and B4) is a general characteristic and can be reproducibly realized by appropriate selection of structural parameters.…”

Section: Observation Of Fm and Afm Interlayer Exchange Couplingmentioning

confidence: 99%

Interlayer exchange coupling in (Ga,Mn)As ferromagnetic semiconductor multilayer systems

Lee¹,

Chung²,

Lee³

et al. 2019

J. Semicond.

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This paper describes interlayer exchange coupling (IEC) phenomena in ferromagnetic multilayer structures, focusing on the unique IEC features observed in ferromagnetic semiconductor (Ga,Mn)As-based systems. The dependence of IEC on the structural parameters, such as non-magnetic spacer thickness, number of magnetic layers, and carrier density in the systems has been investigated by using magnetotransport measurements. The samples in the series show both a typical anisotropic magnetoresistance (AMR) and giant magnetoresistance (GMR)-like effects indicating realization of both ferromagnetic (FM) and antiferromagnetic (AFM) IEC in (Ga,Mn)As-based multilayer structures. The results revealed that the presence of carriers in the non-magnetic spacer is an important factor to realize AFM IEC in this system. The studies further reveal that the IEC occurs over a much longer distance than predicted by current theories, strongly suggesting that the IEC in (Ga,Mn)As-based multilayers is a long-range interaction. Due to the long-range nature of IEC in the (Ga,Mn)As-based systems, the next nearest neighbor (NNN) IEC cannot be ignored and results in multi-step transitions during magnetization reversal that correspond to diverse spin configurations in the system. The strength of NNN IEC was experimentally determined by measuring minor loops that correspond to magnetization flips in specific (Ga,Mn)As layer in the multilayer system.

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Antiferromagnetic exchange coupling between GaMnAs layers separated by a nonmagnetic GaAs:Be spacer

Cited by 9 publications

References 9 publications

The critical role of next-nearest-neighbor interlayer interaction in the magnetic behavior of magnetic/non-magnetic multilayers

The critical role of next-nearest-neighbor interlayer interaction in the magnetic behavior of magnetic/non-magnetic multilayers

Exchange Coupling in Magnetic Semiconductor Multilayers and Superlattices

Interlayer exchange coupling in (Ga,Mn)As ferromagnetic semiconductor multilayer systems

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