Heavy fermions in high magnetic fields
Talk given at Condensed Matter in All the Cities 2020
by Prof. Alix McCollam, High Field Magnet Laboratory (HFML), Radboud University, The Netherlands
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Abstract:
High magnetic field is a powerful tool for the study of heavy fermion systems, where the characteristics and behaviour of the f-electrons drive much of the physics. Magnetic field couples strongly to the relevant magnetic, Kondo, and other exchange interactions, and serves as a relatively straightforward, and reversible, tuning parameter across the complex phase diagrams. Through experiments such as quantum oscillations, we are also able to directly determine the properties of the heavy quasiparticles and the Fermi surface, as magnetic, superconducting and Fermi liquid properties come and go.
In this talk, I will briefly describe some of the key experimental techniques that can be used to study heavy fermions in high magnetic fields, with an outline of the information they yield. I will then focus on recent work we have carried out on the Ce_n T_m In_{3n+2m} family of materials (where T is a transition metal, and n = 1, 2, m = 0, 1, 2), looking specifically at the evolution of the Fermi surface and what it tells us, as the system is field-tuned through antiferromagnetic quantum phase transitions and Lifshitz transitions.
