Magnetism in f -electron superlattices

Abstract

We analyze antiferromagnetism in f electron superlattices. We show that the competition between the Kondo effect and the RKKY interaction in f electron materials is modified by the superlattice structure. Thus, the quantum critical point which separates the magnetic phase and the Fermi liquid phase depends on the structure of the f electron superlattice. The competition between the Kondo effect and the RKKY interaction is also reflected in the magnetic interlayer coupling between different f electron layers. We demonstrate that in the case of weak Kondo effect the magnetic interlayer coupling behaves similar to other magnetic heterostructures without Kondo effect. However, close to the quantum phase transition, the dependence of the interlayer coupling on the distance between the f electron layers is modified by the Kondo effect. Another remarkable effect, which is characteristic for f electron superlattice, is that the magnetic interlayer coupling does vanish stepwise depending on the distance between different f electron layers. As a consequence, the quantum critical point depends also stepwise on this distance.

Probing Electronic and Magnetic Transitions of Short Periodic Nickelate Superlattices Using Synchrotron X-rays

“…Ni XMCD of Ca2NiOsO6 [68]. Furthermore, the magnetic scattering derived from the XMCD spectrum by a Kramers-Kronig (K-K) transformation matches well with the line shape and line position of the scattered intensity, observed in the RXS measurement [30,69,70]. All of these studies confirm the presence of an S=1 state in 2ENO/1LNO SL, which is contrary to the ionic picture, where S=1/2 is expected.…”

Spin fluctuations and superconductivity in layeredf-electron superlattices

“…Due to the proximity to the A layers, small moments are induced into the spacer B layers in a consistent way with the magnetic structures of the A layers. Similar oscillating interlayer magnetic structures and induced moments have been found in DMFT calculations, which support the present FLEX study [30]. Furthermore, such oscillations in the magnetic interlayer coupling have also been commonly found in ferromagnetic superlattices [10][11][12].…”

Superconducting Kondo phase in an orbitally separated bilayer

“…One should notice, though, that in the present case, the critical coupling J c is larger than its value for the single-layer KLM. Indeed, as suggested for the KLM [38,39] and for the PAM [40], an additional metallic layer may enhance the effective RKKY interaction between the local moments, as a result of the induced magnetic order in 033168-3 the conduction layer; simultaneously, the interlayer hopping, t z , weakens Kondo-singlet formation. The latter effect can be seen more clearly if one allows t z /t to vary: as shown in Fig.…”