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Spin waves (SWs) have the potential to reduce the electric energy loss in signal processing networks. The SWs called magnetostatic forward volume waves (MSFVWs) are advantageous for networking due to their isotropic dispersion in the plane of a device. To control the MSFVW flow in a processing network based on yttrium iron garnet, we developed a SW absorber using artificial structures. The mechanical surface polishing method presented in this work can well control extrinsic damping without changing the SW dispersion of the host material. Furthermore, enhancement of the ferromagnetic resonance linewidth over 3 Oe was demonstrated. [ABSTRACT FROM AUTHOR]

The magneto-optical response of the ferromagnetic semiconductor HgCdCr2Se4 at terahertz (THz) frequencies is studied using polarization sensitive THz time-domain spectroscopy. It is shown that the polarization state of broadband terahertz pulses, with a spectrum spanning from 0.2 THz to 2.2 THz, changes as an even function of the magnetization of the medium. Analysing the ellipticity and the rotation of the polarization of the THz radiation, we show that these effects originate from linear birefringence and dichroism, respectively, induced by the magnetic ordering. These effects are rather strong and reach 10² rad/m at an applied field of 1 kG which saturates the magnetization of the sample. Our observation serves as a proof-of-principle showing strong effects of the magnetic order on the response of a medium to electric fields at THz frequencies. These experiments also suggest the feasibility of spin-dependent transport measurements on a sub-picosecond timescale. [ABSTRACT FROM AUTHOR]

It has been found that Ni50Mn35In14B exhibits with increasing temperature a first-order magnetostructural phase transition from a low-magnetization martensitic phase to a high-temperature ferromagnetic austenitic phase at TM∼315 K as observed from magnetization M(T) curves with H=0.05 T. A shift in TM of about 12 K towards lower temperatures has been detected under application of a 5T magnetic field. An asymmetric magnetoresistance (spin-valve-like behavior) has been observed in the vicinity of TM at 304 K after the initial application of magnetic field that could be related to the kinetic arrest and de-arrest of a fractional austenite phase in the vicinity of phase co-existence. A possible origin of a spin-valve-like MR in Ni50Mn35In14B, and its relation to structural, magnetic, and magnetocaloric properties, has been discussed. (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [ABSTRACT FROM AUTHOR]

A method of doping GaAs with Mn using the laser evaporation of a metal target during MOC-hydride epitaxy is developed. The method is used to form both homogeneously doped GaAs:Mn layers and two-dimensional structures, including a δ-doped GaAs:Mn layer and a InxGa1 - xAs quantum well separated by a GaAs spacer with a thickness of d = 3-6 nm. It is shown that, at room temperature, the formed structures have magnetic and magnetooptical properties most probably caused by the presence of MnAs clusters. In the low-temperature region (∼30 K), the anomalous Hall effect is observed. This effect is attributed to the exchange interaction between Mn ions via 2D-channel holes. [ABSTRACT FROM AUTHOR]

A magnetic-field sensor with a high sensitivity of 38 pT/Hz was demonstrated. By utilizing a spinwave differential circuit (SWDC) using two yttrium iron garnet (YIG) films, the temperature sensitivity was suppressed, and the thermal stability of the phase of the spin waves was -0.0095° K-1, which is three orders of magnitude better than a simple YIG-based sensor, ~20° K-1. The SWDC architecture opens the way to design YIG-based magnonic devices. [ABSTRACT FROM AUTHOR]

The magneto-optical response of the ferromagnetic semiconductor HgCdCr2Se4 at terahertz (THz) frequencies is studied using polarization sensitive THz time-domain spectroscopy. It is shown that the polarization state of broadband terahertz pulses, with a spectrum spanning from 0.2 THz to 2.2 THz, changes as an even function of the magnetization of the medium. Analysing the ellipticity and the rotation of the polarization of the THz radiation, we show that these effects originate from linear birefringence and dichroism, respectively, induced by the magnetic ordering. These effects are rather strong and reach 10² rad/m at an applied field of 1 kG which saturates the magnetization of the sample. Our observation serves as a proof-of-principle showing strong effects of the magnetic order on the response of a medium to electric fields at THz frequencies. These experiments also suggest the feasibility of spin-dependent transport measurements on a sub-picosecond timescale. [ABSTRACT FROM AUTHOR]

Magnetotransport properties of an Fe48Mn24Ga28 Heusler-based ferromagnetic shape memory alloy are tracked in a temperature interval that covers both martensitic and austenitic phases. A large temperature hysteresis indicative of a coupled magnetostructural transition from ferromagnetic martensite to paramagnetic austenite is observed on the temperature dependencies of magnetization and electrical resistivity. The temperature dependency of the anomalous Hall-effect coefficient in Fe48Mn24Ga28 cannot be described in terms of skew scattering, side-jump, and intrinsic mechanisms of the anomalous Hall-effect theory. The Hall-effect resistivity in the martensitic state is smaller, but is of the same order of magnitude as in the case of the giant Hall effect in a half-metallic CO2MnAl. Specific features of the temperature dependencies of magnetization, resistivity, magnetoresistance, and ordinary and anomalous Hall-effect coefficients are discussed and the possible routes for increasing Hall-effect resistivity are suggested. [ABSTRACT FROM AUTHOR]

We demonstrate a logic gate based on interference of forward volume spin waves (FVSWs) propagating in a 54 nm thick, 100 μm wide yttrium iron garnet waveguide grown epitaxially on a garnet substrate. Two FVSWs injected by coplanar waveguides were made to interfere constructively and destructively by varying their phase difference, showing an XNOR logic function. The reflected and resonant waves generated at the edges of the waveguide were suppressed using spin wave absorbers. The observed isolation ratio was 19 dB for a magnetic field of ~2.80 kOe (= 223 kA m−1) applied perpendicular to the film. The wavelength and device length were ~8.9 μm and ~53 μm, respectively. Further, the interference state of the SWs was analyzed using three-dimensional radio frequency simulations. [ABSTRACT FROM AUTHOR]