One of the most peculiar properties spin waves in magnetic thin films is nonreciprocal wave propagation, i.e., a dependence on propagation direction. The authors study this effect permalloy thickness varying from 6 to 40 nm and find that difference frequencies can reach several tens MHz. show frequency nonreciprocity mainly caused by asymmetric anisotropies at two surfaces ferromagnetic film. This result important understand recent works interfacial Dzyaloshinskii-Moriya interaction, an...

Spin torque and spin Hall effect nano-oscillators generate high intensity wave auto-oscillations on the nanoscale enabling novel microwave applications in spintronics, magnonics, neuromorphic computing. For their operation, these devices require externally generated currents either from an additional ferromagnetic layer or a material with angle. Here we demonstrate highly coherent field current tunable signals nano-constrictions single 15-20 nm thick permalloy layers oxide interfaces. Using...

We demonstrate magnetization auto-oscillations driven by pure spin currents in Hall nano-oscillators based on CoFeB/Pt bilayers. Despite the very low anisotropic magnetoresistance of CoFeB, a substantial microwave signal power can be detected, even at room temperature, indicating that sizable wave amplitude is generated. Spin torque ferromagnetic resonance measurements reveal generated auto-oscillation frequency lies below CoFeB and therefore well described self-localized bullet mode.

Using both broadband ferromagnetic resonance (FMR) spectroscopy and ab initio calculations, we study the magnetodynamic properties of permalloy $(Py,{\mathrm{Ni}}_{80}{\mathrm{Fe}}_{20})$ ${\mathrm{Py}}_{100\ensuremath{-}x}{\mathrm{M}}_{x}$ films with M as platinum (Pt), gold (Au), or silver (Ag). From uniform FMR mode, extract saturation magnetization $({M}_{S})$, damping $(\ensuremath{\alpha})$, inhomogeneous broadening $(\mathrm{\ensuremath{\Delta}}{H}_{0})$; from first perpendicular...

Short wavelength exchange-dominated propagating spin waves will enable magnonic devices to operate at higher frequencies and data transmission rates. While giant magnetoresistance (GMR)-based magnetic nanocontacts are efficient injectors of waves, the generated wavelengths 2.6 times nano-contact diameter, electrical signal strength remains too weak for applications. Here we demonstrate nano-contact-based wave generation in tunnel junctions observe large-frequency steps consistent with...

The magnetodynamical properties of nanometer-thick yttrium iron garnet films are studied using ferromagnetic resonance as a function temperature. were grown on gadolinium gallium substrates by pulsed laser deposition. First, we found that the damping coefficient increases temperature for different film thicknesses. Second, two dependencies thickness: at room temperature, thickness decreases, while T = 8 K, find to depend only weakly thickness. We attribute this behavior an enhancement...

Spin-polarized electrical transport is investigated in $ Al_{2}O_{3}/Ni_{80}Fe_{20}/Al_{2}O_{3}$ thin films for permalloy thickness between 6 and 20nm. The degree of spin-polarization the current flowing plane film measured through induced spin wave Doppler shift. We find that it decreases as decreases, from 0.72 at 20nm to 0.46 6nm. This decrease attributed a depolarization by surfaces. A model proposed which takes into account contributions different sources electron scattering (alloy...

In this paper, we experimentally demonstrate simultaneous wavelength and orbital angular momentum (OAM) multiplexing/demultiplexing of 10 Gbit/s data streams using a new on-chip micro-component-tunable MEMS-based Fabry-Perot filter integrated with spiral phase plate. the experiment, two wavelengths, each them carrying channels zero nonzero OAMs, form four independent information channels. case spacing between 0.8 nm intensity modulation, power penalties relative to transmission one channel...

The influence of an electrical current on the propagation magnetostatic surface waves is investigated in a relatively thick (40 nm) permalloy film both experimentally and theoretically. Contrary to previously studied thinner films where dominating effect current-induced spin-wave Doppler shift, magnetic field generated by (Oersted field) found induce strong non-reciprocal frequency shift which overcompensates shift. measured induced agreement with developed theory. theory relates sign spin...

We report an electrically pumped 1550 nm MEMS tunable VCSEL with a continuous tuning of 101 at 22 °C. The top MEMS-DBR built-in stress gradient within the dielectric layers is deposited in low-temperature PECVD chamber on InP-based half-VCSEL, structured by surface-micromachining and electrothermally actuated for wavelength tuning. With 2.6 mA threshold current, laser shows maximum CW output power 3.2 mW 1560 nm. MEMS-VCSEL operates single-mode SMSR > 39 dB across entire range. At 36 °C,...

We demonstrate the control of Gilbert damping in 65-nm-thick yttrium iron garnet (YIG) films using a spin-polarized current generated by direct through nanocontact, spin filtered thin Co layer. The magnetodynamics both YIG and layers can be excited pulse-modulated microwave injected nanocontact response detected as lock-in amplified voltage over device. spectra show three clear peaks, two associated with ferromagnetic resonance (FMR) each layer, an additional mode higher wave vector...

We demonstrate the compositional effect on magnetodynamic and auto-oscillation properties of Ni100−xFex/Pt (x = 10–40) nanoconstriction-based spin Hall nano-oscillators. Using spin-torque ferromagnetic resonance performed microstrips, we measure a significant reduction in both damping efficiency with increasing Fe content, which lowers pumping contribution. The strong is primarily attributed to increased saturation magnetization Fe-rich devices. As direct consequence, higher current...

NiFe-Cu-Co trilayer nano-contact spin-torque oscillators (NC-STOs) fabricated on an yttrium-iron garnet (YIG) film were studied in two different modes. In passive mode, i.e. without any NC-STO auto-oscillations, a microwave current through the can excite spin waves (SW) YIG film, and, vice versa, antenna generated SWs be detected by nano-contact. active i.e., presence of significant changes appear spectrum when its frequency approaches that excited YIG. These results demonstrate strong...

This work provides a detailed investigation of the measured in-plane field-swept homodyne-detected ferromagnetic resonance (FMR) spectra an extended Co/Cu/NiFe pseudo-spin-valve stack using nanocontact (NC) geometry. The magnetodynamics are generated by pulse-modulated microwave current, and resulting rectified dc mixing voltage, which appears across NC at resonance, is detected lock-in amplifier. Most notably, we find that NiFe layer composite in nature highly asymmetric, consistent with...

Spin torque oscillators (STOs) are emerging microwave devices that can potentially be used in spin-logic and the next-generation high-speed computing architecture. Thanks to their non-linear nature, STOs easily tunable by magnetic field dc current. Hall nano-oscillators promising types of most current studies focus on localized modes excited. Here, we study using micromagnetic simulations, nature spin-torque-induced excitations nanowire made perpendicular anisotropy (PMA) materials. Our...

Spin pumping at a boundary between yttriumiron garnet (YIG) film and thin platinum (Pt) layer is studied under conditions in which magnetostatic surface spin wave (MSSW, or DamonEshbach mode) excited YIG by narrow strip-line antenna. It shown that the voltage created inverse spin-Hall effect (ISHE) Pt strongly dependent on wavevector of MSSW. For thicknesses 41 0.9m, maximum ISHE corresponds to efficiently MSSW wavevectors does not coincide with absorbed microwave power. thinner (0.175m)...

In this study, we discuss the observation of spin-wave interference generated by magnetic oscillators. We employ micromagnetic simulations for two coherent spin-Hall nanowire oscillators positioned nearby, horizontally or vertically. The nanowires produce circular waves with short wavelengths on order 100 nm, which interfere each other. horizontal configuration, spin exhibit constructive and destructive fringes, indicating amplification cancellation amplitudes, respectively. synchronization...

Continuous-wave (CW) terahertz (THz) photomixing requires compact, widely tunable, mode-hop-free driving lasers. We present a single-mode microelectromechanical system (MEMS)-tunable vertical-cavity surface-emitting laser (VCSEL) featuring an electrothermal tuning range of 64 nm (7.92 THz) that exceeds the commercially available distributed-feedback (DFB) diodes (∼4.8 nm) by factor about 13. first review underlying theory and perform systematic characterization MEMS-VCSEL, with particular...

In this paper the model 1D-GNσ is considered, which concerns 1D Green–Naghdi equations with non-flat bottom and under influence of surface tension, to be widely used in coastal oceanography describe propagation large-wave amplitudes. The purpose show that solution can made by Picard iterative scheme, proves there no loss regularity relative initial condition.

We report frequency-tunable terahertz (THz) generation with a photomixer driven by an ultra-broadband tunable micro-electro-mechanical system vertical-cavity surface-emitting laser (MEMS-VCSEL) and fixed-wavelength VCSEL, as well MEMS-VCSEL mixed distributed feedback (DFB) diode. A total frequency span of 3.4 THz is covered in direct detection mode 3.23 the homodyne mode. The tuning range solely limited dynamic photomixers Schottky diode/photoconductor used experiment.

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