title: Third Law of Thermodynamics and The Shape of the Phase Diagram for Systems With a First-Order Quantum Phase Transition.
abstract: The third law of thermodynamics constrains the phase diagram of systems with a first-order quantum phase transition. For a zero conjugate field, the coexistence curve has an infinite slope at T=0. If a tricritical point exists at T>0, then the associated tricritical wings are perpendicular to the T=0 plane, but not to the zero-field plane. These results are based on the third law and basic thermodynamics only, and are completely general. As an explicit example we consider the ferromagnetic quantum phase transition in clean metals, where a first-order quantum phase transition is commonly observed.
authors.affiliation: Institute for Physical Science and Technology and Department of Physics, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: T R
authors.initials: TR
authors.lastname: Kirkpatrick
authors.affiliation: Department of Physics and Institute of Theoretical Science, University of Oregon, Eugene, Oregon 97403, USA.|Materials Science Institute, University of Oregon, Eugene, Oregon 97403, USA.
authors.forename: D
authors.initials: D
authors.lastname: Belitz