An effective spin Hamiltonian approach to heavy electron metamagnetism

ABSTRACT

We describe a minimal model for metamagnetism, based on a quantum spin Hamiltonian with a single energy scale. Within this model, the metamagnetic critical field is proportional to the temperature where a peak in the linear susceptibility occurs which in turn is proportional to the temperatures where the nonlinear susceptibilities also peak. The thermodynamic properties are derived in a straightforward manner and bear a striking resemblance to observations in such strongly correlated systems as heavy fermion materials. We also consider extensions of the model by including effects such as a mean field and a tilt of the quantisation axis to encompass observed deviations from a minimal metamagnetic behaviour.

KEYWORDS:

• Actinides
• heavy-fermion metals
• Kondo effect
• quantum critical phenomena
• thermal properties
• anisotropic properties

Acknowledgements

We recall with great respect, admiration and affection our long time associations with M. Brian Maple. Brian has been an inspiring source for new models, experiments and with overall a generous, kind and gentle personal approach to science. We look forward to many more years of the same.

Disclosure statement

No potential conflict of interest was reported by the author(s).

ORCID

B. S. Shivaram http://orcid.org/0000-0002-6792-7463