Non-analytic non-equilibrium field theory
Camille Aron (Laboratoire de Physique de l’Ecole Normale Supérieure)
Onsite seminar + zoom (ID: 981 7596 6473, Passcode: fCjZ6d)
The Landau-Ginzburg theory is a cornerstone of modern physics that unifies the various equilibrium phase transitions of matter in a common framework. The free energy, functional of the order parameter, is built on simple principles: locality, symmetry, stability, and analyticity. It is still unclear when and how such a unified principle-based approach can be extended to non-equilibrium phase transitions.
In this talk, I will present the recent theoretical efforts to address the non-equilibrium phase transition which occurs during the resistive switching (RS) of a variety of correlated oxides: their resistivity suddenly drops by several orders of magnitude when subject to a finite voltage bias.
The particular case of RS will lead me to propose to abandon the principle of analyticity of the Landau potential away from thermal equilibrium. This more general question will be addressed in the simpler context of non-equilibrium versions of the Ising model. I will show how the usual φ^4 potential can be deformed by non-analytic operators of intrinsic non-equilibrium nature and use the renormalization group to discuss their low-energy relevance.