Quantum Griffiths effects in itinerant Heisenberg magnets

Orbital polarization in itinerant magnets.

We propose a parameter-free scheme of calculation of the orbital polarization (OP) in metals, which starts with the strong-coupling limit for the screened Coulomb interactions in the random-phase approximation (RPA). For itinerant magnets, RPA can be further improved by restoring the spin polarization of the local-spin-density approximation through the local-field corrections. The OP is then co...

Magnetic anisotropy in itinerant magnets

Far-from-equilibrium spin transport in Heisenberg quantum magnets.

We study experimentally the far-from-equilibrium dynamics in ferromagnetic Heisenberg quantum magnets realized with ultracold atoms in an optical lattice. After controlled imprinting of a spin spiral pattern with an adjustable wave vector, we measure the decay of the initial spin correlations through single-site resolved detection. On the experimentally accessible time scale of several exchange...

Resistivity Minimum in Highly Frustrated Itinerant Magnets.

We study the transport properties of frustrated itinerant magnets comprising localized classical moments, which interact via exchange with the conduction electrons. Strong frustration stabilizes a liquidlike spin state, which extends down to temperatures well below the effective Ruderman-Kittel-Kasuya-Yosida interaction scale. The crossover into this state is characterized by spin structure fac...

Energy and Entropy in Itinerant Magnets

This paper describes a method for calculating short-range magnetic order in itinerant magnets. An energy and an entropy are assigned to configurations of the magnetization. The energy comes from the electronic structure and the entropy from the number of configurations satisfying constraints on the short-range order.