相关论文: Thermally assisted domain walls quantum tunneling …
Quantum tunneling of domain walls out of an impurity potential in a mesoscopic ferromagnetic sample is investigated. Using improved expressions for the domain wall mass and for the pinning potential, we find that the cross-over temperature…
At finite temperature we study the quantum tunneling of magnetization for a small ferromagnetic particle with the biaxial symmetry placed in a magnetic field at an arbitrary angle. We present numerical WKB exponent below the crossover…
Time evolution of tunneling phenomena in medium is studied using a standard model of environment interaction. A semiclassical formula valid at low, but finite temperatures is derived in the form of integral transform for the reduced Wigner…
The macroscopic quantum tunneling of a planar domain wall in a ferromagnetic metal is studied based on the Hubbard model. It is found that the ohmic dissipation is present even at zero temperature due to the gapless Stoner excitation, which…
The depinning of a domain wall in ferromagentic metal via macroscopic quantum tunneling is studied based on the Hubbard model. The dynamics of the magnetization verctor is shown to be governed by an effective action of Heisenberg model with…
The macroscopic quantum tunneling of a planar domain wall in a ferromagnetic metal is studied by use of an instanton method. Based on the Hubbard model, the effective action of the magnetization is derived within the assumption of slow…
We study the domain wall motion in a disordered weak ferromagnet, induced by injecting a spin current from a strong ferromagnet. Starting from the spin diffusion equation describing the spin accumulation in the weak ferromagnet, we…
Quantum vortex tunneling is studied for the case where the Hall and the dissipative dynamics are simultaneously present. For a given temperature, the magnetization relaxation rate is calculated as a function of the external current and the…
The quantum tunneling of the magnetization vector between excited levels are studied theoretically in single-domain ferromagnetic nanoparticles with biaxial crystal symmetry placed in an external magnetic field at an arbitarily directed…
The dynamics of the low energy excitations in a ferromagnet is studied in case a temperature gradient is coupled to the local magnetization. Due to the different time scales of changing temperature and magnetization it is argued that only…
Recent experiments have studied the tunneling current between the edges of a fractional quantum Hall liquid as a function of temperature and voltage. The results of the experiment are puzzling because at "high" temperature (600-900 mK) the…
The temperature dependance of the action in the thin-wall and thick-wall limits is obtained analytically for the $\phi^6$ scalar potential. The nature of the phase transition is investigated from the quantum tunnelling regime at low…
Thermal vector potential formulation is applied to study thermal dynamics of magnetic structures in insulating ferromagnets. By separating variables of the magnetic structure and magnons, the equation of motion for the structure including…
The intended use of a magnetic material, from information storage to power conversion, depends crucially on its domain structure, traditionally crafted during materials synthesis. By contrast, we show that an external magnetic field applied…
Extensive Kerr microscopy studies reveal a strongly temperature dependent domain wall dynamics in Hall-bars made from compressively strained GaMnAs. Depending on the temperature magnetic charging of domain walls is observed and nucleation…
Thermally induced magnetization dynamics is currently a flourishing field of research due to its potential application in information technology. We study the paradigmatic system of a magnetic domain wall in a thermal gradient which is…
We consider Gaussian fluctuations about domain walls embedded in one- or two-dimensional spin lattices. Analytic expressions for the free energy of one domain wall are obtained. From these, the temperature dependence of experimentally…
Quantum mechanical tunneling of atoms is increasingly found to play an important role in many chemical transformations. Experimentally, atom-tunneling can be indirectly detected by temperature-independent rate constants at low temperature…
We investigate the motion of a domain wall in the presence of a dynamical hyperfine field. At temperature T high compared to the hyperfine coupling, the nuclear spins create a spatially random potential landscape, with dynamics dictated by…
We develop a phenomenological model of superconductivity near a domain wall in a ferromagnet. In addition to the electromagnetic interaction of the order parameter with the ferromagnetic magnetization, we take into account the possibility…