title: Coherent quasiparticles with a small fermi surface in lightly doped Sr(3)Ir(2)O(7).
abstract: We characterize the electron doping evolution of (Sr_{1-x}La_{x})_{3}Ir_{2}O_{7} by means of angle-resolved photoemission. Concomitant with the metal insulator transition around x≈0.05 we find the emergence of coherent quasiparticle states forming a closed small Fermi surface of volume 3x/2, where x is the independently measured La concentration. The quasiparticle weight Z remains large along the entire Fermi surface, consistent with the moderate renormalization of the low-energy dispersion, and no pseudogap is observed. This indicates a conventional, weakly correlated Fermi liquid state with a momentum independent residue Z≈0.5 in lightly doped Sr_{3}Ir_{2}O_{7}.
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: de la Torre
authors.affiliation: School of Physics and Astronomy, The University of Edinburgh, James Clerk Maxwell Building, Mayfield Road, Edinburgh EH9 2TT, United Kingdom.
authors.forename: E C
authors.initials: EC
authors.lastname: Hunter
authors.affiliation: Centre de Physique Théorique, École Polytechnique, CNRS, 91128 Palaiseau Cedex, France.
authors.forename: A
authors.initials: A
authors.lastname: Subedi
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland.
authors.forename: S
authors.initials: S
authors.lastname: McKeown Walker
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland.
authors.forename: A
authors.initials: A
authors.lastname: Tamai
authors.affiliation: Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom.
authors.forename: T K
authors.initials: TK
authors.lastname: Kim
authors.affiliation: Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Hoesch
authors.affiliation: London Centre for Nanotechnology and UCL Centre for Materials Discovery, University College London, London WC1E 6BT, United Kingdom.
authors.forename: R S
authors.initials: RS
authors.lastname: Perry
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland and Centre de Physique Théorique, École Polytechnique, CNRS, 91128 Palaiseau Cedex, France and Collège de France, 11 place Marcelin Berthelot, 75005 Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Georges
authors.affiliation: Department of Quantum Matter Physics, University of Geneva, 24 Quai Ernest-Ansermet, 1211 Geneva 4, Switzerland and Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland and SUPA, School of Physics and Astronomy, University of St Andrews, St Andrews, Fife KY16 9SS, United Kingdom.
authors.forename: F
authors.initials: F
authors.lastname: Baumberger