| Autor: |
Efremov DV; Department of Physics and Centre for the Science of Material, Loughborough University, Loughborough LE11 3TU, United Kingdom., Shtyk A; Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA., Rost AW; School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, United Kingdom.; Max Planck Institute for Solid State Research, Heisenbergstrasse 1, 70569 Stuttgart, Germany., Chamon C; Department of Physics, Boston University, Boston, Massachusetts 02215, USA., Mackenzie AP; School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, Fife KY16 9SS, United Kingdom.; Max Planck Institute for Chemical Physics of Solids, Noethnitzer Strasse 40, 01187 Dresden, Germany., Betouras JJ; Department of Physics and Centre for the Science of Material, Loughborough University, Loughborough LE11 3TU, United Kingdom. |
| Abstrakt: |
A wide variety of complex phases in quantum materials are driven by electron-electron interactions, which are enhanced through density of states peaks. A well-known example occurs at van Hove singularities where the Fermi surface undergoes a topological transition. Here we show that higher order singularities, where multiple disconnected leaves of Fermi surface touch all at once, naturally occur at points of high symmetry in the Brillouin zone. Such multicritical singularities can lead to stronger divergences in the density of states than canonical van Hove singularities, and critically boost the formation of complex quantum phases via interactions. As a concrete example of the power of these Fermi surface topological transitions, we demonstrate how they can be used in the analysis of experimental data on Sr_{3}Ru_{2}O_{7}. Understanding the related mechanisms opens up new avenues in material design of complex quantum phases. |
