We study coherent spin transport through a one-dimensional double-barrier resonant-tunneling structure containing a finite, localized Zeeman segment in its central cavity. The Zeeman term is diagonal in spin, so the two spin channels experience opposite local potentials ± V_1 and do not mix. This simplicity exposes a spatial parity selection rule: the spin splitting of the nth cavity resonance is Δ E_n ≃ 2V_1W_n , where W_n is the probability weight of the quasibound state inside the segment. A centered segment is an even-parity perturbation, so odd modes split strongly while even modes are protected by their central node; displacing the segment inverts this selectivity. The peak polarization obeys a universal scaling |P_z|≃ 2Q_n^2/(1+2Q_n^2) , with Q_n=Δ E_n/Γ _n the ratio of splitting to resonance linewidth, which collapses the dependence on Zeeman strength, segment width, and position onto a single curve. For a GaAs-like model, the first resonance reaches 93–95
The properties of nonlinear stationary waves and solitons in a warm three-component plasma were studied. A feature of the plasma under study was a special signature of charges of species, when light particles and particles of an intermediate mass have the same charge sign, and heavy particles are charged oppositely. Another feature was the chosen light particle distribution, the super-nonextensive Tsallis distribution. The study was performed within the gas dynamic approximation. A linear analysis of the waves was performed and a dispersion equation was derived. As a result, an expression for the linear velocity of sound was obtained. Normalization to this expression of soliton velocities provides the Mach number. Nonlinear analysis of waves by the Sagdeev pseudopotential method was performed. It was found that stationary subsonic periodic waves, supersonic and hypersonic solitons may exist in the plasma under study. The effect of the temperature of the fraction of light particles, their relative concentration and their parameter of non-extensiveness on the conditions for the existence of hypersonic solitons was studied. Profiles of physical quantities in supersonic and hypersonic solitons were calculated. It was shown that hypersonic solitons can have abnormally high Mach numbers, a giant amplitude of the potential, and a high degree of compression of the fraction with intermediate mass particles. An abnormal dependence of the amplitude of the concentration of intermediate mass particles in hypersonic solitons on the Mach number was found. The dependence turned out to be nonmonotonic. At the same time, the dependence of the potential amplitude in hypersonic solitons on the Mach number is increasing at least on the studied parameter intervals.
A magnetic field applied parallel to a Rashba spin-orbit-coupled two-dimensional electron gas, proximized by a conventional superconductor, gives rise to a topological superconducting phase hosting antichiral edge states formed by co-propagating Majorana fermions. These modes remain robust against edge corrugations in systems with non-planar boundaries, provided that the characteristic radius of curvature of the boundary exceeds the Fermi wavelength of the two-dimensional electron gas. In this work, we revisit the properties of this phase and investigate the local density of states (LDOS) both at the edges and in the bulk. We identify distinctive spectral signatures near the Fermi energy associated with the antichiral Majorana modes, providing experimentally accessible fingerprints of the phase.
We present and discuss results on a specific simple system involving quantum tunneling: namely, the “Bose–Hubbard dimer” or “Bose–Josephson junction (BJJ)”. A physical realization of this system is provided by a Bose–Einstein condensate (BEC) in a double-well optical lattice. We show that, despite its simplicity, the system exhibits remarkable macroscopic quantum behavior that can be understood in many cases by a semiclassical “global phase space” approach but which in fact requires a fully quantum treatment in certain regions of parameter space. We compare the results of our theoretical studies with existing experimental data and predict new phenomena that should be observed in future experiments. Among these new phenomena are the existence of tunneling between two self-trapped states that are unconnected in the semiclassical approximation.
This study investigates the mechanical behavior of two-dimensional TH-graphyne nanosheets using molecular dynamics simulations. The pristine nanosheet exhibits significant mechanical anisotropy, with Young’s moduli of 204.77 GPa and 270.19 GPa and ultimate tensile strengths of 51.03 GPa and 92.73 GPa along the x- and y-directions, respectively. The influence of crack orientation (0°–90°) shows up to a 54.5
