Tuning the Dimensionality of the Heavy Fermion Compound CeIn3

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][1]; see the Perspective by [Coleman][2] ) 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. [1]: /lookup/doi/10.1126/science.1183376 [2]: /lookup/doi/10.1126/science.1186253