title: Quasiparticle dynamics across the full Brillouin zone of Bi2Sr2CaCu2O8+δ traced with ultrafast time and angle-resolved photoemission spectroscopy.
abstract: A hallmark in the cuprate family of high-temperature superconductors is the nodal-antinodal dichotomy. In this regard, angle-resolved photoemission spectroscopy (ARPES) has proven especially powerful, providing band structure information directly in energy-momentum space. Time-resolved ARPES (trARPES) holds great promise of adding ultrafast temporal information, in an attempt to identify different interaction channels in the time domain. Previous studies of the cuprates using trARPES were handicapped by the low probing energy, which significantly limits the accessible momentum space. Using 20.15 eV, 12 fs pulses, we show for the first time the evolution of quasiparticles in the antinodal region of Bi2Sr2CaCu2O8+δ and demonstrate that non-monotonic relaxation dynamics dominates above a certain fluence threshold. The dynamics is heavily influenced by transient modification of the electron-phonon interaction and phase space restrictions, in stark contrast to the monotonic relaxation in the nodal and off-nodal regions.
authors.affiliation: Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, USA.
authors.forename: Georgi L
authors.initials: GL
authors.lastname: Dakovski
authors.affiliation: Condensed Matter and Magnet Science, Materials Physics and Applications Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, USA.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Durakiewicz
authors.affiliation: Physics of Condensed Matter and Complex Systems, Theoretical Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, USA.
authors.forename: Jian-Xin
authors.initials: JX
authors.lastname: Zhu
authors.affiliation: Department of Physics, Temple University , Philadelphia, Pennsylvania 19122, USA.
authors.forename: Peter S
authors.initials: PS
authors.lastname: Riseborough
authors.affiliation: Condensed Matter Physics and Materials Science, Brookhaven National Laboratory , Upton, New York 11973, USA.
authors.forename: Genda
authors.initials: G
authors.lastname: Gu
authors.affiliation: Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, USA.
authors.forename: Steve M
authors.initials: SM
authors.lastname: Gilbertson
authors.affiliation: Materials Physics and Applications, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, USA.
authors.forename: Antoinette
authors.initials: A
authors.lastname: Taylor
authors.affiliation: Center for Integrated Nanotechnologies, Materials Physics and Applications Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, USA.
authors.forename: George
authors.initials: G
authors.lastname: Rodriguez