Related papers: Field-induced quasi-particle coherence effects in …
High field specific heat, Cp, and magnetic susceptibility, \c{hi}, measurements were performed on the quasi-two dimensional Heisenberg antiferromagnet [Cu(pyz)2(pyO)2](PF6)2. While no Cp anomaly is observed down to 0.5 K in zero magnetic…
We study an influence of a finite magnetic field on a small spin-degenerate quantum dot with even number of electrons, attached to metallic leads. It is shown that, under certain conditions, the low energy physics of the system can be…
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…
High energy resolution spectroscopic studies of quantum magnets have proven to be extremely valuable in directly accessing magnetodynamics quantities, such as energy barriers, magnetic interactions, lifetime of excited states and…
We study macroscopic quantum coherence in antiferromagnetic molecular magnets in the presence of magnetic fields. Such fields generate artificial tunnel barriers with externally tunable strength. We give detailed semi-classical predictions…
Magnetic anisotropy is a key feature of rare earth materials from permanent magnets to heavy fermions. We explore the complex interplay of Kondo physics and anisotropy, and their effect on different experimental probes of magnetic…
We present a theory of the low-energy excitations of a ferromagnetic metal nanoparticle. In addition to the particle-hole excitations, which occur in a paramagnetic metal nanoparticle, we predict a branch of excitations involving the…
We investigate the effect of an applied magnetic field on resonant tunneling of electrons through the bound states of self-assembled InAs quantum dots (QDs) embedded within an (AlGa)As tunnel barrier. At low temperatures (no more than 2 K),…
The spin-phase interference effects are studied analytically in resonant quantum tunneling of the N\'{e}el vector between degenerate excited levels in nanometer-scale single-domain antiferromagnets in the absence of an external magnetic…
Tunneling anisotropic magnetoresistance (TAMR) effect, discovered recently in (Ga,Mn)As ferromagnetic semiconductors, arises from spin-orbit coupling and reflects the dependence of the tunneling density of states in a ferromagnetic layer on…
The quantum interference effects induced by the topological phase are studied analytically in biaxial antiferromagnets with an external magnetic field at an arbitrarily angle. This study provides a nontrivial generalization of the Kramers…
Quasiperiodic structures possess long range positional order, but are freed of constraints imposed by translational invariance. For spins interacting via Heisenberg couplings, one may expect therefore to find novel magnetic configurations…
We discuss the behaviour of a quantum Hall system when two Landau levels with opposite spin and combined filling factor near unity are brought into energetic coincidence using an in-plane component of magnetic field. We focus on the…
The single-particle energy spectrum of a two-dimensional electron gas in a perpendicular magnetic field consists of equally-spaced spin-split Landau levels, whose degeneracy is proportional to the magnetic field strength. At integer and…
We present details about an experimental method based on the Landau Zener model which allows to measure very small tunnel splittings $\Delta$ in molecular clusters Fe8. The measurements are performed with an array of micro-SQUIDs. The…
We present the first observations of cylindrical symmetry breaking in highly excited diamagnetic hydrogen with a small crossed electric field, and we give a semiclassical interpretation of this effect. As the small perpendicular electric…
We consider transport through a single-molecule magnet strongly coupled to metallic electrodes. We demonstrate that for half-integer spin of the molecule electron- and spin-tunneling \emph{cooperate} to produce both quantum tunneling of the…
We show that in suitable anisotropic ferromagnets, both stable and metastable ``tilted'' phases occur, in which the magnetization ${\vec M}$ makes an angle between zero and $180$ degrees with the externally applied ${\vec H}$. Tuning either…
The systems exhibiting quantum phase transitions (QPT) are investigated within the Ising model in the transverse field and Heisenberg model with easy-plane single-site anisotropy. Near QPT a correspondence between parameters of these models…
We discuss the orbital effect of a tilted magnetic field on the quantum Hall effect in parabolic quantum wells. Many-body states realized at the fractional 1/3 and 1/2 filling of the second electronic subband are studied using finite-size…