Related papers: Exponential equilibration by slow cooling in the p…
The low temperature relaxation of the magnetization in magnetic molecular solids such as Fe$_8$ is studied using Monte Carlo simulations. A set of rate equations is developed to understand the simulations, and the results are compared. The…
Motivated by experiments on NiGa2S4, we discuss characteristic (finite temperature) properties of spin S = 1 quantum antiferromagnets on the triangular lattice. Several recent theoretical studies have suggested the possibility of…
In $d$-electron systems, there can also be intricate interplay between Kondo coupling and magnetic interactions as that in $f$-electron systems, but the underlying mechanism remains elusive. Here, using inelastic neutron scattering, we…
Static and dynamic properties of magnetically soft amorphous ferromagnets have been studied analytically and numerically within random-field and random-anisotropy models. External field and coherent anisotropy that are weak compared to…
We present non-equilibrium physics in spin ice as a novel setting which combines kinematic constraints, emergent topological defects, and magnetic long range Coulomb interactions. In spin ice, magnetic frustration leads to highly degenerate…
By Monte Carlo simulations in the canonical ensemble, we have studied the magnetic anisotropy in Fe/Dy amorphous multilayers. This work has been motivated by experimental results which show a clear correlation between the magnetic…
In thin magnetic films with strong perpendicular anisotropy and strong demagnetizing field two ordered phases are possible. At low temperatures, perpendicularly oriented magnetic domains form a striped pattern. As temperature is increased…
Frustrated magnets are one class of fascinating materials that host many intriguing phases such as spin ice, spin liquid and complex long-range magnetic orderings at low temperatures. In this work we use first-principles calculations to…
The conformal anomaly indicates the breaking of conformal symmetry (angle-preserving transformations) in the quantum theory by quantum fluctuations and is a close cousin of the gravitational anomaly. We show, for the first time, that the…
In the present paper the problem of the relaxation of magnetization to equilibrium (i.e., with no magnetization) is investigated numerically for a variant of the well-known model introduced by Bohr to study the diamagnetism of electrons in…
We study the zero temperature coarsening dynamics in an Ising chain in presence of a dynamically induced field that favors locally the `-' phase compared to the `+' phase. At late times, while the `+' domains still coarsen as $t^{1/2}$, the…
We present results of Monte Carlo simulations, using parallel tempering, on the three- and four-dimensional Edwards-Anderson Ising spin glass with Gaussian couplings at low temperatures with free boundary conditions. Our results suggest…
Muon spin rotation (muSR) experiments reveal unconventional spin freezing and dynamics in the two-dimensional (2D) triangular lattice antiferromagnet NiGa2S4. Long-lived disordered Ni-spin freezing (correlation time > 10-6 s at 2 K) sets in…
We report new experimental results obtained onthe insulating spin glass CdCrInS_4. Our experimental setup allows a quantitative comparison between thethermo-remanent magnetization and the autocorrelation of spontaneous fluctuations of…
Hidden magnetic order of Sr$_2$Ir$_{1-x}$Rh$_x$O$_4$, $x = 0.05$ and 0.1, has been studied using muon spin relaxation spectroscopy. In zero applied field and weak longitudinal fields ($\mu_0H_L \lesssim 2$~mT), muon spin relaxation data can…
We investigate the effects of layered quenched disorder on the behavior of planar magnets, superfluids, and superconductors by performing large-scale Monte-Carlo simulations of a three-dimensional randomly layered XY model. Our data provide…
A comparative study of the non-equilibrium magnetic phenomena (magnetic blocking, memory, exchange bias and aging effect) has been presented for ferrimagnetic Co$_{1.75}$Fe$_{1.25}$O$_4$ (CFO) and its composite with non-magnetic BaTiO$_3$…
We perform equilibrium parallel-tempering simulations of the 3D Ising Edwards-Anderson spin glass in a field. A traditional analysis shows no signs of a phase transition. Yet, we encounter dramatic fluctuations in the behaviour of the…
We study partially occupied lattice systems of classical magnetic dipoles which point along randomly oriented axes. Only dipolar interactions are taken into account. The aim of the model is to mimic collective effects in disordered…
Doppler cooling on a narrow transition is limited by the noise of single scattering events. It shows novel features, which are in sharp contrast with cooling on a broad transition, such as a non-Gaussian momentum distribution, and…