Related papers: Tunneling Rate for Superparamagnetic Particles by …
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…
Tunneling is one of the most bizarre phenomena in quantum mechanics. An attempt to understand it led to the next natural question of how long does a particle need to tunnel a barrier. The latter gave rise to several definitions such as the…
In this paper, we attempt the theoretical modeling of the magnetic tunnel junctions with embedded magnetic and nonmagnetic nanoparticles (NPs). A few abnormal tunnel magnetoresistance (TMR) effects, observed in related experiments, can be…
Spin effects in the tunneling regime of strong field ionization of hydrogenlike highly charged ions in linearly as well as circularly polarized laser fields are investigated. The impact of the polarization of a laser field on the spin…
When charge current passes through a normal metal that exhibits spin Hall effect, spin accumulates at the edge of the sample in the transverse direction. We predict that this spin accumulation, or spin voltage, enables quantum tunneling of…
The tunneling rate, with exact prefactor, is calculated to first order in \hbar for a closed FRW universe filled with perfect fluid violating the strong energy condition. The calculations are performed by applying the dilute-instanton…
Below 360 mK, Fe magnetic molecular clusters are in the pure quantum relaxation regime and we show that the predicted square-root time relaxation is obeyed, allowing us to develop a new method for watching the evolution of the distribution…
Using a three-dimensional quasiclassical technique we explore molecular double ionization by a linearly polarized, infrared (800~nm) 27~fs laser pulse. For intensities ranging from the tunneling to the over-the-barrier regime, we identify…
We elucidate the multi-particle transport of pair- and spin-tunnelings in strongly correlated interfaces. Not only usual single-particle tunneling but also interaction-induced multi-particle tunneling processes naturally arise from a…
We develop an instantonic calculus to derive an analytical expression for the thermally-assisted tunneling decay rate of a metastable state in a fully connected quantum spin model. The tunneling decay problem can be mapped onto the Kramers…
The Hawking-Moss tunneling rate for a field described by the Dirac-Born-Infeld action is calculated using a stochastic approach. We find that the effect of the non-trivial kinetic term is to enhance the tunneling rate, which can be…
Tunneling in quantum field theory is worth understanding properly, not least because it controls the long term fate of our universe. There are however, a number of features of tunneling rate calculations which lack a desirable transparency,…
We consider tunneling transitions between states separated by an energy barrier in a simple field theoretical model. We analyse the case of soliton creation induced by collisions of a few highly energetic particles. We present…
Tunnelling is one of the most paradigmatic and evocative phenomena of quantum physics, underlying processes such as photosynthesis and nuclear fusion, as well as devices ranging from SQUID magnetometers to superconducting qubits for quantum…
Time evolution of tunneling phenomena proceeding in thermal medium is studied using a standard model of environment interaction. A semiclassical probability formula for the particle motion in a metastable state of one dimensional system put…
We study the escape rate of a particle in a metastable potential in presence of a dissipative bath coupled to the momentum of the particle. Using the semiclassical bounce technique, we find that this rate is exponentially enhanced. In…
Massive particles are radiated from black holes through the Hawking mechanism together with the more familiar radiation of massless particles. For $E >= m$, the emission rate is identical to the massless case. But $E < m$ particles can also…
How much time does a tunneling wave packet spent in traversing a barrier? Quantum mechanical calculations result in zero time inside a barrier . In the nineties analogous tunneling experiments with microwaves were carried out. The results…
This chapter takes a microscopic view of quantum tunneling of magnetization (QTM) in single-molecule magnets (SMMs), focusing on the interplay between exchange and anisotropy. Careful consideration is given to the relationship between…
The electron tunneling in half metallic manganite tunnel junctions is studied by using a quantum mechanically treated double exchange model. We show that the stimulation of spin excitations, caused by the strong Hund's coupling between the…