Related papers: Macroscopic Quantum Phase Interference in Antiferr…
Fully-relativistic first-principles calculations of the Fe(001) surface demonstrate that resonant surface (interface) states may produce sizeable tunneling anisotropic magnetoresistance in magnetic tunnel junctions with a single magnetic…
This article presents a review on the theoretical and the experimental developments on macroscopic quantum tunneling and phase transition of the escape rate in spin systems. We present the basic ideas with simplified calculations so that it…
In fractional quantum Hall systems, quasiparticles of fractional charge can tunnel between the edges at a quantum point contact. Such tunneling (or backscattering) processes contribute to charge transport, and provide information on both…
We describe a tunneling spectroscopy technique in a double bilayer graphene heterostructure where momentum-conserving tunneling between different energy bands serves as an energy filter for the tunneling carriers, and allows a measurement…
We report magnetic field spectroscopy measurements in carbon nanotube quantum dots exhibiting four-fold shell structure in the energy level spectrum. The magnetic field induces a large splitting between the two orbital states of each shell,…
The tunneling between the two ground states of an Ising ferromagnet is a typical example of many-body tunneling processes between two local minima, as they occur during quantum annealing. Performing quantum Monte Carlo (QMC) simulations we…
Starting from the Hamiltonian operator of the noncompensated two-sublattice model of a small antiferromagnetic particle, we derive the effective Lagrangian of a biaxial antiferromagnetic particle in an external magnetic field with the help…
We argue that the tunneling between two 2D electron gases in a weak magnetic field is of resonance character, and involves a long lifetime excitonic state of an electron and hole {\it uniformly spread} over cyclotron orbits. We find that…
The observation of quantum conductance oscillations in mesoscopic systems has traditionally required the confinement of the carriers to a phase space of reduced dimensionality. While electron optics such as lensing and focusing have been…
We study spin tunneling in a magnetic nanoparticle with biaxial anisotropy that is free to rotate about its anisotropy axis. Exact instanton of the coupled equations of motion is found that connects degenerate classical energy minima. We…
The magnetic state of atomically thin semiconducting layered antiferromagnets such as CrI$_3$ and CrCl$_3$ can be probed by forming tunnel barriers and measuring their resistance as a function of magnetic field ($H$) and temperature ($T$).…
We investigate the energy spectrum of the biaxial spin systems with magnetic field along the hard anisotropy axis by using the complex periodic orbit theory. All important features of the system appearing in whole energy range, such as…
We theoretically investigate magnetoresistance (MR) effects in connection with spin filtering in quantum-coherent transport through tunnel junctions based on non-magnetic/semimagnetic heterostructures. We find that spin filtering in…
Quantum interference phenomena in the conductivity of mesoscopic ferromagnets are considered, particularly with regard to the effects of geometric phases acquired by electrons propagating through regions of spatially varying magnetization…
The evolution of the quantum wave packet describing an atom trapped in the surface-tip junction of the scanning tunneling microscope is investigated by using the time-dependent Schroedinger equation, and by a quasi-classical Hamiltonian…
We demonstrate a possibility to manipulate the magnetic coupling between two nanomagnets with a help of ac electric field. In the scheme suggested the magnetic coupling in question is mediated by a magnetic particle contacting with both of…
For a two-sublattice antiferromagnet the Lagrangian is constructed taking into account Berry phase whose form is matched to the quantum-mechanical Heisenberg Hamiltonian. Tunnel effects are analyzed taking into account the crystallographic…
Quantum-classical escape-rate transition has been studied for two general forms of magnetic anisotropy in ferrimagnetic or antiferromagnetic particles. It is found that the range of the first-order transition is greatly reduced as the…
We compute tunneling in a quantum field theory in 1+1 dimensions for a field potential $U(\Phi)$ of the asymmetric double well type. The system is localized initially in the ``false vacuum''. We consider the case of a {\em compact space}…
The charge transport in a dirty 2-dimensional electron system biased in the presence of a lateral potential barrier under magnetic field is theoretically studied. The quantum tunneling across the barrier provides the quantum interference of…