Tomonari Kato

Tuning the Dimensionality of the Heavy Fermion Compound CeIn3

2D Quantum Critical Transitions Quantum critical transitions occur at near-zero temperatures when the properties of quantum matter are tuned by an external parameter such as the magnetic field or pressure. Heavy fermion materials, which have effective charge carrier masses hundreds of times heavier than the bare electron mass, have emerged as a prototypical system for studying these transitions. Now, Shishido et al. (p. 980; see the Perspective by Coleman) use a heavy fermion compound to experimentally realize a new type of quantum phase transition where the tuning parameter is the dimensionality of the system. They engineer a family of superlattices made up of a fixed number of layers of the conventional metal LaIn3 and varying numbers of layers of the heavy fermion material CeIn3. As the number of layers of CeIn3 is decreased, the system gradually changes character from three- to two-dimensional, with corresponding changes in its transport properties. A quantum phase transition is achieved by varying the dimension of a heavy fermion superlattice. Condensed-matter systems that are both low-dimensional and strongly interacting often exhibit unusual electronic properties. Strongly correlated electrons with greatly enhanced effective mass are present in heavy fermion compounds, whose electronic structure is essentially three-dimensional. We realized experimentally a two-dimensional heavy fermion system, adjusting the dimensionality in a controllable fashion. Artificial superlattices of the antiferromagnetic heavy fermion compound CeIn3 and the conventional metal LaIn3 were grown epitaxially. By reducing the thickness of the CeIn3 layers, the magnetic order was suppressed and the effective electron mass was further enhanced. Heavy fermions confined to two dimensions display striking deviations from the standard Fermi liquid low-temperature electronic properties, and these are associated with the dimensional tuning of quantum criticality.

Lower critical fields of superconducting PrFeAsO1-y single crystals

We have studied the lower critical fields

Evidence for Fully Gapped Superconductivity from Microwave Penetration Depth Measurements in PrFeAsO1-y Single Crystals

{H}_{c1}

Disorder and flux pinning in superconducting pnictide single crystals

of superconducting iron oxipnictide

Transformation experiment on sodium feldspar using deformation-Cubic Anvil, D-CAP 700, with synchrotron X rays

{\text{PrFeAsO}}_{1\ensuremath{-}y}

Formation of Jadeite from Plagioclase: Constraints on the P-T-t Conditions of Shocked Meteorites

single crystals for

Kinetics of diffusion-controlled growth of Ringwoodite and Mg-perovskite

\mathbit{H}

Lower critical fields and the anisotropy in PrFeAsO1−y single crystals

parallel and perpendicular to the

Confinement of heavy fermion to two-dimension by the fabrication of the artificial superlatattice

ab

Deformation experiment on fayalite using deformation-Cubic Anvil, D-CAP 700, with synchrotron X rays

planes. Measurements of the local magnetic induction at positions straddling the sample edge by using a miniature Hall-sensor array clearly resolve the first flux penetration from the Meissner state. The temperature dependence of