Related papers: Efficiency of spin-injection terahertz oscillator
The electron transmission $T$ is evaluated through waveguides, in which the strength of the spin-orbit interaction(SOI) $\alpha$ is varied periodically, using the transfer-matrix technique. It is shown that $T$ exhibits a {\it…
We present the spin quantum Otto machine under different optimization criterion when function either as a heat engine or a refrigerator. We examine the optimal performance of the heat engine and refrigerator depending on their efficiency,…
Terahertz electromagnetic radiation is extremely useful for numerous applications such as imaging and spectroscopy. Therefore, it is highly desirable to have an efficient table-top emitter covering the 1-to-30-THz window whilst being driven…
Spintronic terahertz emitters are novel, broadband and efficient sources of terahertz radiation, which emerged at the intersection of ultrafast spintronics and terahertz photonics. They are based on efficient spin-current generation,…
Frequency response optimized integrators considering second order derivative are proposed in this paper. Based on the proposed numerical integrators, and others which also consider second order derivative, this paper puts forward a novel…
Properties are discussed of a ferromagnetic junction of the type "rod contacting with film". Very high current density of the order of $10^9$ A/cm$^2$ may be achieved in the contact region. We show it can lead to inversion of population of…
We propose an experimental scheme to determine the spin-transfer torque efficiency excited by the spin-orbit interaction in ferromagnetic bilayers from the measurement of the longitudinal magnetoresistace. Solving a diffusive spin-transport…
The article contains calculation of the efficiency of the ideal thermomagnetic engine whose working body is ferromagnetic has been suggested. Suggested method being applicable to any heat engine operating on the basis of structural phase…
We consider a finite time quantum heat engine analogous to finite time classical Carnot heat engine with a working substance of spin half particles. We study the efficiency at maximum $\dot{\Omega}$ figure of merit of the quantum heat…
A mesoscopic description of spin-transfer effect is proposed, based on the spin-injection mechanism occurring at the junction with a ferromagnet. The effect of spin-injection is to modify locally, in the ferromagnetic configuration space,…
Generation of spin imbalance in nonmagnetic semiconductors is crucial for the functioning of many spintronic devices. An attractive design of spin injectors into semiconductors is based on a spin pumping from a precessing ferromagnet,…
We report the first experimental demonstration that interface microstructure limits diffusive electrical spin injection efficiency across heteroepitaxial interfaces. A theoretical treatment shows that the suppression of spin injection due…
Spintronic Terahertz Emitters (STE) represent a significant advancement in source technology, exploiting the ultrafast demagnetization process of spin-electrons to unveil a 30THz wide, gapless spectrum, accessible through femtosecond lasers…
In order to enhance spin injection efficiency from ferromagnetic (FM) metal into a two-dimensional electron gas (2DEG), we introduce another FM metal and two tunnel barriers (I) between them to investigate the current polarization in such…
The stochastic efficiency [G. Verley et al., Nat. Commun. 5, 4721 (2014)] was introduced to evaluate the performance of energy-conversion machines in micro-scale. However, such an efficiency generally diverges when no heat is absorbed while…
We report on the spin-polarized electron injection through an Fe(100)/InAs(100) junction. The circularly polarized electroluminescence of injected electrons from epitaxially grown Fe thin film into InAs(100) in an external magnetic field is…
The interaction of terahertz (THz) radiation with high-frequency spin resonances in complex magnetic materials is central for modern ultrafast magnonics. Here we demonstrate strong variations of the excitation efficiency of the sub-THz…
We study the performance of a quantum Otto heat engine with two spins coupled by a Heisenberg interaction, taking into account not only the mean values of work and efficiency but also their fluctuations. We first show that, for this system,…
The three dimensional harmonic oscillator model including a cranking term is used for an energy variational calculation. Energy minima are found under variation of the three oscillator frequencies determining the shape of the system for…
The energetic efficiencies of rocked ratchets reported in the literature typically lie in the sub-percent range. We discuss the problem of optimization of the energetic efficiency of a ratchet, and show that considerably higher efficiencies…