Room temperature spasing of surface plasmon polaritons at 1.46 μm wavelength has been demonstrated by sandwiching a gold-film plasmonic waveguide between optically pumped InGaAs quantum-well gain media. The spaser exhibits narrowing, the expected transverse-magnetic polarization, and mirror feedback provided cleaved facets in 1-mm long cavity fabricated with flip-chip approach. 1.06-μm pump-threshold ~60 kW/cm2 is good agreement calculations. architecture readily adaptable to all-electrical...

Abstract Luminescent gold nanocrystals (AuNCs) are a recently-developed material with potential optic, electronic and biological applications. They also demonstrate energy transfer (ET) acceptor/sensitization properties which have been ascribed to Förster resonance (FRET) and, lesser extent, nanosurface (NSET). Here, we investigate AuNC acceptor interactions three structurally/functionally-distinct donor classes including organic dyes, metal chelates semiconductor quantum dots (QDs). Donor...

Experiments are reported that demonstrate current-perpendicular-to-the-plane giant magnetoresistance devices can be switched repeatably between the high- and low-resistance states by passing current vertically through structure. The lithographically patterned devices, having diameters in range of 0.3–0.7 μm, operate at room temperature exhibit distinctly separate switching soft hard layers. Designs for magnetoelectronic random access memory utilize this scheme storing reading information.

Magnetic field effects (MFEs) in the luminescence and photoconductivity of organic crystals such as anthracene have been known since 1960s. While engaged a project to use spin polarized current manipulate electroluminescence (EL) light emitting diodes based on bilayer tris(8-hydroxyquinoline) aluminum (Alq3) N,N′-Di(naphthalen-1-yl)-N,N′diphenyl-benzidine (NPB), we observed MFE similar those reported anthracene. The consist an increase EL with increasing magnetic few percent for small...

To understand the importance of band gap to magnetic ordering in semiconductors, we have studied effect particle size on ferromagnetic Curie temperature semiconducting EuS. We synthesized capped ∼20 nm EuS nanoparticles using a single-source precursor, [Eu(S2CNiBu2)3Phen] decomposed trioctylphosphine. The been characterized by X-ray powder diffraction, TEM, and susceptibility measurements as function field. temperature, based Arrott plots, is depressed 1−2 K from bulk value.

Low noise sensors with low power consumption are needed for sensing the biomagnetic potentials produced by human body. Compared to their electrical counterparts, noninvasive and noncontact. A strain-modulated FeCo-Hf/AlScN-based sensor a bandwidth of 3.4 kHz magnetic spectral density at 1 59.5 pT/ <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\surd $ </tex-math></inline-formula> Hz before demodulation...

We demonstrate that guided resonant modes can be readily observed in asymmetrical photonic crystal slabs on high-index substrates. In spite of the high radiative loss associated with all optical these cases, are found to give rise strong high-Q features transmission spectra. Since structures far more robust and easier fabricate than free-standing membranes used previous studies modes, detailed relevant phenomena implementation proposed applications greatly simplified.

Spin-transfer torque film stacks and devices having in-plane magnetization were irradiated using a cobalt-60 gamma source. Samples also exposed to 2 MeV 220 protons. Measurements of vs. field, ferromagnetic resonance, tunnel magnetoresistance performed on the before after exposure these sources no changes observed in associated material properties. same show bit-state or write performance.

Magnetoelectric (ME) cantilever resonators have been successfully employed as magnetic sensors to measure low fields; however, high relative resolution enabling magnetometry in fields is lacking. Here, we present on-chip silicon based ME microelectromechanical (MEMS) doubly clamped which can be utilized sensitivity, power sensors. The resonator a fully suspended thin film heterostructure composed of an active magnetoelastic layer (Fe0.3Co0.7), strain coupled piezoelectric signal/excitation...

Developments in magnetoelectronics are advancing by combination of once disparate areas research magnetic materials, semiconductor electronics, and optoelectronics. We explore the integration materials with organic semiconductors. Because small spin–orbit coupling these minimizes spin relaxation, they may be useful spintronic applications. Motivated a theoretical investigation into spin-dependent exciton formation that predicts magnetoluminescence valve effect, we attempt to manipulate...

Abstract The discovery of low-dimensional metallic systems such as high-mobility metal oxide field-effect transistors, the cuprate superconductors and conducting interfaces ( e.g. , LaAlO 3 /SrTiO ) has stimulated research into nature electronic transport in two-dimensional given that seminal theory for disordered metals predicts state cannot exist two dimensions (2D). In this report, we demonstrate existence a metal–insulator transition (MIT) highly RuO 2 nanoskins with carrier...

Abstract The ability to tune both magnetic and electric properties in magnetoelectric (ME) composite heterostructures is crucial for multiple transduction applications including energy harvesting or field sensing, other devices. While large ME coupling achieved through interfacial strain-induced rotation of anisotropy magnetostrictive/piezoelectric multiferroic has been demonstrated, there are presently certain restrictions achieving a full control magnetism an extensive operational dynamic...

The behavior of chemical and magnetic interfaces is explored using diffuse x-ray resonant scattering (XRMS) for CoFe thin films with varying interfacial roughnesses. A comparison the versus shows distinct differences in these two related as roughness increased. Such changes appear to be correlated hysteresis interface, measured by tracking XRMS intensity a function applied field.

Half-metallic (HM) ferromagnetic materials have recently drawn intense interests due to their potential use in magnetoelectronic devices. Co-based Heusler alloys of the type CO/sub 2/MnX (X=Si,Ge), predicted be HM by first principles band structure calculations, are particular interest since they alone possess Curie temperatures excess 900 K. Since spin polarization (P) is believed sensitive antisite defects that likely occur vapor-quenched thin film synthesis, single crystals Co/sub (X=Si,...

Electroluminescence (EL) from organic light-emitting diodes can be surprisingly sensitive (∼20%) to modest magnetic fields B (0–2T). The origin of this magnetic-field effect has not been clearly identified, although the in some devices resembles that delayed fluorescence anthracene, which originates magnetic-field-dependent singlet-exciton production via triplet-triplet annihilation (TTA). Here, we test role TTA at low (∼80mT) by measuring transient EL and employing dc drive levels so...

A compact and versatile source of coherent surface-plasmon polaritions (SPPs) is demonstrated by end-coupling a laser diode operating at 1.46 microm to plasmonic waveguide integrated on the same microchip. With an optimized overlap between spatial-modes planar-stripe waveguide, high coupling efficiency approximately 36% achieved, that computations show could approach 60% with smaller, readily achievable gaps waveguide. This electrically-activated source, available SPP power limited only...

Magnetoelectric materials present a unique opportunity for electric field-controlled magnetism. Even though strain-mediated multiferroic heterostructures have shown unprecedented increase in magnetoelectric coupling compared to single-phase materials, further improvements must be made before ultra-low power memory, logic, magnetic sensors, and wide spectrum antennas can realized. This work presents how enhanced by simultaneously exploiting multiple strain engineering approaches composed of...

Magnetoelectric (ME)-based magnetometers have garnered much attention as they boast ultra-low-power systems with a small form factor and limit of detection in the tens picotesla. The highly sensitive low-power electric readout from ME sensor makes them attractive for near DC low-frequency AC magnetic fields platforms continuous signature monitoring. Among multiple configurations current sensors, most rely on exploiting mechanically resonant characteristics released microelectromechanical...

The magnetic response of microdevices is significantly enhanced at structural resonance allowing for improved sensitivity and signal-to-noise ratio. Here, free-standing thin film CoFe bridge resonators have been fabricated investigated. It shown that the strong field dependence fundamental frequency a function orientation due to stress-induced anisotropy. These devices may offer new approach developing fully integrated resonant sensing technology.

By studying the variation in magnetic interfacial structure using diffuse x-ray resonant scattering, underlying connections between chemical and interfaces are uncovered utilized to understand how intrinsic properties influence behavior of interface. considering effect competing energies (dipolar, anisotropy, exchange) at rough interface, it becomes clear forces can lead a reduction disorder.

The hysteretic behavior of interfacial magnetic moments for CoFe thin films with varying roughness is determined in an element specific manner by monitoring the applied field dependence specular and off-specular (diffuse) contributions to x-ray resonant scattering signal. Increasing generates a larger variation relative coercive associated moment comparison bulk.

As the size of giant magneto resistive (GMR) devices continues to decrease into submicrometer regime, demagnetizing field from magnetic layers will increase very high values, prohibiting switching with a reasonably small current. The most feasible way reduce it is make thinner. Single NiFeCo and CoFe films as well multilayers consisting these various underlayers have been deposited by rf diode sputtering in field. becomes nonmagnetic at 15, 10, 6 Å when using Ta, Si3N4, Cu underlayers,...

Experiments are reported that demonstrate the asymmetric switching behavior earlier in vertical giant magnetoresistance devices arises from solid disk geometry of device produces a magnetic singularity at center. Annular having 0.1 μm center hole and 0.5 outer diameter shown to switch symmetrically with an Amperian field.

The pyrite Fe1−xCoxS2 (0.25⩽x⩽0.9) was predicted to be half metal, insensitive Fe–Co disorder. To verify its metallicity, we have grown single crystals of (x=0.35, 0.5, 0.75, 0.9, and 1). Crystals up a few mm in size by temperature gradient (923–873 K) solution growth from Te melts, which showed high crystalline quality scanning electron microscopy, x-ray diffraction, magnetic measurements. A half-metallic magnetization 1±0.03μB per Co atom found for x=0.35–0.9. Point contact Andreev...

A far-field microscopy approach is introduced that measures the transmittance of surface plasmon polaritons across gaps in plasmonic waveguides. Local intensity monitored through radiation scattered from discontinuities placed before and after gap. An unusually broad range gap sizes, 30 nm to 16 μm, reported for optically thick, 5 μm wide Au stripe-waveguides excited at 860 wavelength. Transmittances 100% a remain as high 50% 1 Finite-element analysis yields transmittances agreement with...