April 08, 02:00 PM, Paris Time (GMT +2)
Emergence by infinite symmetry, application to the Nernst effect
After a generic review of the dynamical symmetry approach to many-body quantum states, I will focus on infinite-dimensional symmetries of quantum Hall states, 2D superconductors and superinsulators.
The infinite number of constraints accounts for the robustness of these ground states while the representation theory of the symmetry algebra leads to the quantum numbers of allowed excitations, predicting, e.g. exactly the observed quantum Hall plateaus.
Finally, I will show how the infinite dynamical symmetry of superconductors in a magnetic field implies a universal bound k_B ln 2 on the entropy per vortex per layer, thereby explaining the puzzling result of a recent experiment on the Nernst effect in these systems.