Tuning the Dimensionality of the Heavy Fermion Compound CeIn 3

Concepts

Natural SciencesPhysicsCondensed Matter PhysicsQuantum MechanicsSolid State PhysicsAntiferromagnetic MaterialsAntiferromagnetismElectron CorrelationLow-dimensional SolidsLow-dimensional SystemsStrongly Correlated Electron SystemsEffective MassHeavy Fermion SystemsLow-dimensional AntiferromagnetismQuantum CriticalityStrongly Correlated ElectronsSuperlatticesTuningTwo-dimensional Electron Systems

TL;DR

Low‑dimensional, strongly interacting condensed‑matter systems often show unusual electronic properties, while heavy‑fermion compounds possess highly correlated electrons with large effective masses and a three‑dimensional electronic structure. The study aims to experimentally realize a two‑dimensional heavy‑fermion system by controllably tuning its dimensionality. The authors fabricated epitaxial artificial superlattices of CeIn₃ and LaIn₃ to achieve the dimensional tuning. Reducing CeIn₃ layer thickness suppresses magnetic order and further enhances effective mass, while two‑dimensional heavy fermions exhibit pronounced deviations from Fermi‑liquid behavior linked to quantum‑criticality tuning.

Abstract

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.