Submitted on April 9, 2007
Accepted on July 18, 2007
Bilayer 3He: A Simple Two-Dimensional Heavy Fermion System with Quantum Criticality
Michael Neumann 1,
Ján Nyéki 1,
Brian Cowan 1,
John Saunders 1*
1 Department of Physics, Royal Holloway, University of London, Egham, Surrey TW20 0EX, UK.
* To whom correspondence should be addressed.
John Saunders , E-mail: j.saunders{at}rhul.ac.uk
Two-dimensional 3He provides a simple model for the experimental investigation of the emergence of quantum complexity in a strongly correlated Fermi system. We report the observation of two-dimensional two-band heavy fermion behavior in bilayer films of 3He atoms, when adsorbed on the surface of graphite pre-plated by a solid bilayer of 4He. Thermodynamic measurements on this system show that the relevant control parameter is the total density of the 3He film. The 3He bilayer system can be driven towards a quantum critical point at which the effective mass appears to diverge, inter-band coupling vanishes and a local moment state appears. It opens a new testing ground for theories of quantum criticality in heavy fermion materials.
