In this paper, the spin transfer torque (STT) and the exchange coupling of the Josephson junctions containing the interesting cases of diffusive/ballistic-triplet/singlet ferromagnetic superconductor (FS) materials are investigated. First, the diffusive FS 1/F c/FS 2 structures with F c being a junction consisting of ferromagnetic and normal metal parts as well as insulating barriers are investigated. Secondly, the ballistic Josephson junction containing the triplet chiral p/wave FS reservoirs is studied. Using the Nazarov quantum circuit theory for the diffusive structures, it is found that the antiparallel/parallel or vice versa parallel/antiparallel transition of the favorable exchange coupling takes place due to the appearance of the on

It is commonly believed that the significant energy saving advantages are belonged to the logic circuits which operate at low temperature as less energy is needed for cooling them to the threshold temperature after operation. Also, nanoscale thermal management, efficient energy usage in nanoscale and especially thermal optimization are the most challenging issues, while dealing with the new generation of transistors as the miniaturizing unlimitedly the silicon channels of the transistors has resulted in an increase in the energy consumption of computers and the leakage currents. In this paper, the non-Fourier thermal attitudes of well-known two-dimensional crystalline materials of graphene, blue phosphorene, germanene, silicene and MoS2 as

Due to the importance of the transistors in nano-electronics technology, the accurate study of these nano-devices is an essential field of research. Taking into account the non-Fourier nature of heat transfer with considering the three-dimensional structure of the silicon nano-devices, are the challenges in transistor analysis which have not been studied precisely yet. Using the Monte-Carlo method for solving the Boltzmann equation, two actual three-dimensional silicon transistors are accurately simulated. First, the accuracy of the method is verified by the investigation of heat transport in different regimes for a cuboid. Then, the procedure is used to simulate a 2-D silicon nano-device. The obtained results present good consistency with

In this paper, the intact subject of 3-D MOSFETs is studied. Three well-known 3-D MOSFET nano-devices, including a common three dimensional silicon MOSFET, the FinFET, and the Tri-Gate, are dealt. Firstly, by implying the three dimensional non-linear Dual-Phase-Lag method, the obtained results are verified with the existent data. Contemporaneously, the important parameter B= τ t/τ q, which is prerequisite for DPL modeling, is found for the 3-D silicon. The adjusted parameter B, is used to study the 3-D transistors with temperature-dependent thermal characteristics. It is found that taking into account such relevancy, makes the overall trends of distributions unmodified. Finally, the effect of contemplating the graphene sheet heat remover

The classical model of the Fourier’s law is known as the most common constitutive relation for thermal transport in various engineering materials. Although the Fourier’s law has been widely used in a variety of engineering application areas, there are many exceptional applications in which the Fourier’s law is questionable. This paper gathers together such applications. Accordingly, the paper is divided into two parts. The first part reviews the papers pertaining to the fundamental theory of the phase-lagging models and the analytical and numerical solution approaches. The second part wrap ups the various applications of the phase-lagging models including the biological materials, ultra-high-speed laser heating, the pro

Numerical simulation of non-linear non-Fourier heat conduction within a nano-scale metal–oxide–semiconductor field-effect transistor (MOSFET) is presented under the framework of Dual-Phase-Lag model including the boundary phonon scattering. The MOSFET is modeled in four cases of: (I) thin silicon slab, (II) including uniform heat generation, (III) double-layered buried oxide MOSFET with uniform heat generation in silicon-dioxide layer, and (IV) high-k/metal gate transistor. First, four cases are studied under four conditions of (a) constant bulk and (b) constant film thermal properties, (c) temperature-dependent properties of bulk silicon, and (d) temperature-dependent thermal properties of film silicon. The heat source and boundary con

The one-dimensional non-linear non-Fourier heat conduction within a thin film of solid argon is numerically investigated under the framework of the Dual-Phase-Lagging (DPL) model including the boundary phonon scattering. The thermal properties of the solid argon including the thermal conductivity and sound group velocity are considered to be temperature-dependent, and the results are compared with those obtained from the Molecular-Dynamics simulation for the following cases: (I) constant applied temperature and (II) constant applied heat flux at the left boundary. In addition, each case is studied under two conditions of constant and temperature-dependent volumetric heat capacity. It is concluded that the combination of the DPL model with t

This paper investigates the numerical simulation of non-Fourier transient heat transfer in a two-dimensional sub-100?nm metal-oxide-semiconductor field-effect transistor (MOSFET). The dual-phase-lag (DPL) model with a specific normalization procedure is introduced for the modeling of nanoscale heat transport. The boundary conditions are selected similar to what existed in a real MOSFET device, both uniform and non-uniform heat generations within the transistor are applied, and the end parts of the top boundary which are in contact with the metallic material are left open. A temperature-jump boundary condition is used on all boundaries in order to consider the boundary phonon scattering at micro and nanoscale. A three-level finite difference

We consider how superconducting correlations influence spin-transfer torques in ferromagnetic superconductors. It is demonstrated that there is a novel torque arising from particle-hole interference that depends on the U (1) phase associated with the superconducting order parameter. We also show that there is an equilibrium exchange torque between two ferromagnetic superconductors in contact via a normal metal mediated by Andreev states. The latter equilibrium magnetic torque is also sensitive to spin-resolved phase differences in the superconducting order parameters as well as to an externally applied phase difference.

We present a theoretical study of the Josephson coupling of two superconductors that are connected through a diffusive contact consisting of noncollinear ferromagnetic domains. The leads are conventional s-wave superconductors with a phase difference of phiv. Firstly, we consider a contact with two domains with magnetization vectors misoriented by an angle θ. Using the quantum circuit theory, we found that in addition to the charge supercurrent, which shows a 0–π transition relative to the angle θ, a spin supercurrent with a spin polarization normal to the magnetization vectors flows between the domains. While the charge supercurrent is odd in phiv and even in θ, the spin supercurrent is even in phiv and odd in θ. Furthermore, with a

[en] We numerically study the Josephson coupling of two s-wave superconductors which are connected through a diffusive contact made of two ferromagnetic domains with the magnetization vectors misoriented by an angle θ. The assumed superconducting leads are conventional s-wave type with the phase difference of φ. Using the quantum circuit theory, we find that in addition to the charge supercurrent, which shows a 0-π transition relative to the angle θ, the spin supercurrent with a spin polarization normal to the magnetization vectors will flow through the contact. Our results present a 0-π quantum phase transition as a function of the wave vector, Qξ. Finally, we investigate the spin supercurrent in an extended magnetic texture with mul

We investigate the Josephson current between two superconductors (S) which are connected through a diffusive magnetic junction with a complex structure (F c). Using the quantum circuit theory, we obtain the phase diagram of 0 and π Josephson couplings for F c being an insulator-ferromagnet-insulator (IFI) double barrier junction or an IFNFI structure (where N indicates a normal-metal layer). Compared to a simple SFS structure, we find that the width of the transition, defined by the interval of exchange fields in which a 0− π transition is possible, is increased by insulating barriers at the interfaces and also by the presence of the additional N layer. The widest transition is found for symmetric F c structures. The symmetric SIFNFIS p