Related papers: Magnetic hard-direction ordering in anisotropic Ko…
We investigate theoretically and experimentally the singlet-triplet Kondo effect induced by a magnetic field in a molecular junction. Temperature dependent conductance, $G(T)$, is calculated by the numerical renormalization group, showing a…
We study the effect of crystal field anisotropy in the underscreened $S=1$ Kondo lattice model. Starting from the two orbital Anderson lattice model and including a local anisotropy term, we show, through Schrieffer-Wolff transformation,…
The local magnetic anisotropy of a typical crystalline compound is usually attributed to the combined effect of crystal electric fields and spin-orbit coupling. We show that this simple local picture is transformed in heavy-fermion…
We study the spin-resolved transport through single-level quantum dots strongly coupled to ferromagnetic leads in the Kondo regime, with a focus on contact and material asymmetry-related effects. By using the numerical renormalization group…
Formation of magnetically ordered state in the Kondo lattices is treated within the degenerate $s-f$ exchange and Coqblin-Schrieffer models. The Kondo renormalizations of the effective coupling parameter, magnetic moment and spin excitation…
The renormalization group equations describing a finite 2DXY system with fourfold anisotropy are solved in two steps, in order to study the magnetic transition to paramagnetism in an ultrathin film. First, the equations are linearized near…
We present a new type of temperature driven spin reorientation transition (SRT) in thin films. It can occur when the lattice and the shape anisotropy favor different easy directions of the magnetization. Due to different temperature…
The ability to tune the competition between the in-plane and out-of-plane orientation of magnetization provides a means to construct thermal sensors with a sharp spin re-orientation transition at specific temperatures. We have observed such…
In normal metals, the magnetic moment of impurity spins disappears below a characteristic Kondo temperature, TK, where coupling with the conduction-band electrons produces an entangled state that screens the local moment. In contrast,…
The effect of a magnetic field on the equilibrium spectral and transport properties of a single-molecule junction is studied using the numerical renormalization group method. The molecule is described by the Anderson-Holstein model in which…
We propose a scheme to realize the Kondo model with tunable anisotropy using alkaline-earth atoms in an optical lattice. The new feature of our setup is Floquet engineering of interactions using time-dependent Zeeman shifts, that can be…
From a systematic study of the electrical resistivity $\rho(T,H)$, magnetic susceptibility $\chi(T,H)$, isothermal magnetization $M(H)$ and the specific heat $C(T,H)$, a temperature-magnetic field ($T$-$H$) phase diagram has been…
Motivated by the recent measurements of Kondo resistivity in thin films and wires, where the Kondo amplitude is suppressed for thinner samples, the surface anisotropy for magnetic impurities is studied. That anisotropy is developed in those…
The compound V$_5$S$_8$ can also be represented by V$_{1.25}$S$_2$, a transition metal dichalcogenide (TMDC) with excess V. Very few TMDCs show magnetism and/or Kondo effect. Among them, the sister compounds VSe$_2$ and VTe$_2$ are recently…
$R$V${_6}$Sn${_6}$ ($R$ = Y, Gd - Tm, Lu) single crystals are synthesized by Sn-flux method and their physical properties are characterized by magnetization, resistivity, and specific heat measurements. Powder X-ray diffraction patterns of…
A detailed analysis of the Kondo effect of a magnetic impurity in a zigzag graphene nanoribbon is addressed. An adatom is coupled to the graphene nanoribbon via a hybridization amplitude $\Gamma_{imp}$ in a hollow or top site configuration.…
We study numerically the low-temperature electronic transport properties of a single-ion magnet with uniaxial and transverse spin anisotropies. We find clear signatures of a Kondo effect caused by the presence of a transverse (zero-field)…
We report the evolution of crystallographic structure, magnetic ordering and electronic transport in thin films of full-Heusler alloy Co$_2$MnSi deposited on (001) MgO with annealing temperatures ($T_A$). By increasing the $T_A$ from…
Magnetic impurities bridging nanocontacts and break junctions of nearly magnetic metals may lead to permanent moments, analogous to the giant moments well known in the bulk case. A numerical renormalization group (NRG) study shows that,…
We present a theory of the magnetotransport in weakly disordered metals close to an antiferromagnetic quantum-critical point. The anisotropic scattering from critical spin fluctuations is strongly influenced by weak but isotropic scattering…