Fermi surface transformation at the pseudogap critical point of a cuprate superconductor

Dec. 1 11:15-11:40

*Yawen Fang1, Gaël Grissonnanche1,2,3, Anaëlle Legros 3,4, Simon Verret3, Francis Laliberté 3, Clément Collignon 3, Amirreza Ataei3, Maxime Dion 3, Jianshi Zhou5, David Graf 6, Michael J. Lawler1,7, Paul A. Goddard8, Louis Taillefer3,9, B. J. Ramshaw 1,9
Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY, USA1
Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY, USA2
Département de physique, Institut quantique, and RQMP, Université de Sherbrooke, Sherbrooke, Québec, Canada3
SPEC, CEA, CNRS-UMR 3680, Université Paris-Saclay, Gif-sur-Yvette, France4
Materials Science and Engineering Program, Department of Mechanical Engineering, University of Texas at Austin, Austin, TX, USA5
National High Magnetic Field Laboratory, Tallahassee, FL, USA6
Department of Physics, Applied Physics and Astronomy, Binghamton University, Binghamton, NY, USA7
Department of Physics, University of Warwick, Coventry, UK8
Canadian Institute for Advanced Research, Toronto, Ontario, Canada9

The nature of the pseudogap phase remains a major puzzle in our understanding of cuprate high-temperature superconductivity. Whether or not this metallic phase is defined by any of the reported broken symmetries, the topology of its Fermi surface remains a fundamental open question. Here we use angle-dependent magnetoresistance (ADMR) to measure the Fermi surface of the La1.6–xNd0.4SrxCuO4 cuprate. Outside the pseudogap phase, we fit the ADMR data and extract a Fermi surface geometry that is in excellent agreement with angle-resolved photoemission data. Within the pseudogap phase, the ADMR is qualitatively different, revealing a transformation of the Fermi surface. We can rule out changes in the quasiparticle lifetime as the sole cause of this transformation. We find that our data are most consistent with a pseudogap Fermi surface that consists of small, nodal hole pockets, thereby accounting for the drop in carrier density across the pseudogap transition found in several cuprates.

Keywords: Fermi surface, pseudogap, cuprate superconductor