B. I. Kochelaev

Why could electron spin resonance be observed in a heavy fermion Kondo lattice

AbstractWe develop a theoretical basis for understanding the spin relaxation processes in Kondo lattice systems with heavy fermions as experimentally observed by electron spin resonance (ESR). The Kondo effect leads to a common energy scale that regulates a logarithmic divergence of different spin kinetic coefficients and supports a collective spin motion of the Kondo ions with conduction electrons. We find that the relaxation rate of a collective spin mode is greatly reduced due to a mutual cancellation of all the divergent contributions even in the case of the strongly anisotropic Kondo interaction. The contribution to the ESR linewidth caused by the local magnetic field distribution is subject to motional narrowing supported by ferromagnetic correlations. The developed theoretical model successfully explains the ESR data of YbRh2Si2 in terms of their dependence on temperature and magnetic field.

Orbital order parameter in La0.95Sr0.05MnO3probed by electron spin resonance

The temperature dependence of the electron-spin resonance linewidth in La0.95Sr0.05MnO3 has been determined and analyzed in the paramagnetic regime across the orbital ordering transition. From the temperature dependence and the anisotropy of linewidth and

Low temperature properties of the electron spin resonance in YbRh2Si2

g

EPR study of the dynamic spin susceptibility in heavily doped YBa2Cu3O6+δ

-value the orbital order can be unambiguously determined via the mixing angle of the wave functions of the

Phase Transitions and Spin Relaxation in La0.95Sr0.05MnO3

e_{\rm g}

Orbital Order and Spin Relaxation in La0.95Sr0.05MnO3

-doublet. The linewidth shows a similar evolution with temperature as resonant x-ray scattering results.

INTRINSIC ELECTRON PARAMAGNETIC RESONANCE IN LA2-XSRXCUO4 : MANIFESTATION OF THREE SPIN POLARONS

We present the field and temperature behavior of the narrow electron spin resonance (ESR) response in YbRh 2 Si 2 well below the single ion Kondo temperature. The ESR g-factor reflects a Kondo-like field and temperature evolution of the Yb 3+ magnetism. Measurements toward low temperatures (> 0.5 K) have shown distinct crossover anomalies of the ESR parameters upon approaching the regime of a well-defined heavy Fermi liquid. Comparison with the field dependence of specific heat and electrical resistivity reveal that the ESR parameters can be related to quasiparticle mass and cross section and, hence, contain inherent heavy electron properties.

Intrinsic EPR in La2-xSrxCuO4: Manifestation of Three-Spin Polarons

Abstract We report on measurements of the dynamic spin susceptibility of the CuO 2 -planes on single crystals of YBa 2 Cu 3 O 6+δ using EPR techniques. Intrinsic signals due to the existence of paramagentic chain fragments (pcf) show a behaviour revealing the opening of a spin gap above the superconducting phase-transition temperature. This can be directly compared with the results as observed from neutron scattering and NMR experiments.

EPR STUDY OF THE DYNAMIC SPIN SUSCEPTIBILITY IN HEAVILY DOPED YBA2CU3O6+DELTA

We present a model calculation of the paramagnetic-resonance linewidth in La0.95Sr0.05MnO3. Both the temperature and the angular dependencies can be described by contributions from the crystal field due to the cooperative Jahn–Teller transition.

Magnetic resonance on LiCuVO4

We analyze the temperature and angular dependence of the paramagnetic-resonance linewidth of La0.95Sr0.05MnO3. The observed anisotropy can be well described by the crystal field contributions originated by the Jahn–Teller distortion. The critical behavior of the linewidth at the Jahn–Teller transition is found to be directly related with the orbital order.