Related papers: Macroscopic quantum tunneling in magnetic nanostru…
This chapter presents a review on spin transfer torque in magnetic tunnel junctions. In the first part, we propose an overview of experimental and theoretical studies addressing current-induced magnetization excitations in magnetic tunnel…
Quantum tunneling between two potential wells in a magnetic field can be strongly increased when the potential barrier varies in the direction perpendicular to the line connecting the two wells and remains constant along this line. An…
Injection of spins into semiconductors is essential for the integration of the spin functionality into conventional electronics. Insulating layers are often inserted between ferromagnetic metals and semiconductors for obtaining an efficient…
We present detailed measurements of the discrete electron-tunneling level spectrum within nanometer-scale cobalt particles as a function of magnetic field and gate voltage, in this way probing individual quantum many-body eigenstates inside…
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…
In a nanomagnet (whose total spin S< 1000), very small polarized currents can lead to magnetic reversal. Treating on the same footing the transport and magnetic properties of a nanomagnet connected to magnetic leads via tunneling barriers,…
A tunnel magnetic junction is considered with magnetic hard and magnetic soft layers of cubic symmetry. The magnetic switching is analyzed of the layers by a magnetic field perpendicular to the initial magnetizations. In such a situation,…
A new mechanism different from the spin accumulation picture is proposed for the current induced magnetization switching in magnetic tunnel junctions by taking into account the effect of the electron electron interaction. We found in tunnel…
We examine transport through a quantum dot coupled to three ferromagnetic leads in the regime of weak tunnel coupling. A finite source-drain voltage generates a nonequilibrium spin on the otherwise non-magnetic quantum dot. This spin…
Macroscopic quantum tunneling of the phase is a fundamental phenomenon in the quantum dynamics of superconducting nanocircuits. The tunneling rate can be controlled in such circuits, where the potential landscape for the phase can be tuned…
How does magnetism behave when the physical dimension is reduced to the size of nanostructures? The multiplicity of magnetic states in these systems can be very rich, in that their properties depend on the atomic species, the cluster size,…
Inspired by a recent paper$^*$ by C. Fefferman, J. Shapiro and M. Weinstein, we investigate quantum tunneling for a Hamiltonian with a symmetric double well and a uniform magnetic field. In the simultaneous limit of strong magnetic field…
We present a theoretical study of momentum-resolved tunneling between parallel two-dimensional conductors whose charge carriers have a (pseudo-)spin-1/2 degree of freedom that is strongly coupled to their linear orbital momentum. Specific…
We measure the low-temperature resistance of permalloy break junctions as a function of contact size and the magnetic field angle, in applied fields large enough to saturate the magnetization. For both nanometer-scale metallic contacts and…
We describe in this short review the influence of discrete symmetries in complex quantum dots on the Kondo co-tunneling through these nano-objects. These discrete symmetries stem from the geometrical structure of the tunneling devices (e.g…
A model for describing structural pointlike defects in nanoscaled ferromagnetic materials is presented. Its details are explicitly developed whenever interacting with a vortex-like state comprised in a thin nanodisk. Among others, our model…
We present new results on quantum tunneling between deep potential wells, in the presence of a strong constant magnetic field. We construct a family of double well potentials containing examples for which the low-energy eigenvalue splitting…
We investigate the effect of surface anisotropy in a spherical many-spin magnetic nanoparticle. By computing minor loops, two-dimensional (2D) and 3D energyscape, and by investigating the behavior of the net magnetization, we show that in…
Quantum tunneling, a phenomenon which has no counterpart in classical physics, is the quantum-mechanical process by which a microscopic particle can transition through a potential barrier even when the energy of the incident particle is…
We demonstrate that transport spectroscopy of single molecular magnets shows signatures of quantum tunneling at low temperatures. We find current and noise oscillations as function of bias voltage due to a weak violation of spin selection…