Regensburg 2019 – wissenschaftliches Programm
TT 15.9: Vortrag
Montag, 1. April 2019, 17:00–17:15, H23
Finite electronic correlations and two-dome superconductivity across a clean nematic quantum phase transition — •Pascal Reiss1, David Graf2, Amir A Haghighirad1,3, William Knafo4, Loïc Drigo4,5, Matt Bristow1, Andrew J Schofield6, and Amalia I Coldea1 — 1Clarendon Laboratory, University of Oxford, UK — 2National High Magnetic Field Laboratory, Florida State University, Tallahassee, USA — 3Institut fur Festkörperphysik, Karlsruhe Institute of Technology, Germany — 4Laboratoire National des Champs Magnétiques Intenses (LNCMI-EMFL), Toulouse, France — 5Géosciences Environnement Toulouse (CNRS), Toulouse, France — 6School of Physics and Astronomy, University of Birmingham, UK
In the proximity of a nematic quantum critical point, electronic nematic fluctuations have been identified as a candidate for enhancing superconductivity in various unconventional superconductors. However, the coexistence of long-range magnetic order has hindered detailed studies of nematic criticality. To address this challenge, we combine chemical pressure in FeSe1−xSx to suppress long-range magnetic order, and physical pressure to study the uncovered, clean nematic quantum phase transition. Using magneto-transport and quantum oscillations measurements, we trace the strength of electronic correlations and their role played in promoting superconductivity. We demonstrate that electronic correlations remain finite, the Fermi surface suffers a Lifshitz transition, and superconductivity is weakened across the nematic quantum phase transition. We interpret these results in light of recent theoretical and experimental advances, and sample quality.