Bulletin of the American Physical Society
APS March Meeting 2013
Volume 58, Number 1
Monday–Friday, March 18–22, 2013; Baltimore, Maryland
Session Z1: Invited Session: Time- and Angle- Resolved Photoemission Spectroscopy of Complex Materials
11:15 AM–2:15 PM,
Friday, March 22, 2013
Room: Ballroom I
Sponsoring Units: DCMP GIMS
Chair: Thomas Devereaux, SLAC National Acceleratory Laboratory
Abstract ID: BAPS.2013.MAR.Z1.4
Abstract: Z1.00004 : Time-resolved ARPES and f-electron coherence*
1:03 PM–1:39 PM
Preview Abstract Abstract
(Los Alamos National Laboratory, MPA-CMMS Group, Los Alamos, NM 87544, USA)
The coherence temperature, T*, sets an important energy scale in correlated f-electron systems. In this scale the hybridization gap opens at or in the vicinity of the Fermi level and the gap magnitude scales with effective quasiparticle mass. The new quasiparticle bands are heavy, as demonstrated by their small dispersion, and the quasiparticle lifetime is long, as seen by the narrow width of the peaks. Unless magnetic ordering suppresses the gap or mass enhancement is observed due to, e.g., magnetic excitations, the gap scales with effective mass in a universal manner across the heavy fermion systems. Possible deviations from this pattern, e.g. a small finite gap persisting at high temperatures above T* require models beyond a mean-field approach, and may be understood within e.g. the model of periodic array of Anderson impurities with correlations described by coupling to specific boson modes. \\ Self-energy approach is commonly used in ARPES of correlated systems. The coherent part of the self-energy corresponding to the gap formation is reduced at high temperatures, and the incoherent part corresponds to quasiparticle scattering. The coherent term in the self-energy expresses the mixing of f and d bands and is directly responsible for repulsion, producing the hybridization gap. This theoretical framework provides a direction towards understanding quasiparticle dynamics in correlated electron systems through ultrafast self-energy measurements and modeling. Here we show examples of time-resolved ARPES measurements of f-electron systems, providing valuable information about the evolution of coherence and the dynamics of the related quasiparticle states. \\ References \\ 1) Phys. Rev. B 84, 161103 (Rapid Comm.) (2011). \\ 2) Phys. Rev. B 84, 161101 (Rapid Comm) (2011).\\ 3) Phys. Rev. Lett. 106, 207402 (2011).\\ 4) J.Phys.C. 23, 094211 (2011).\\ 5) Rev. Sci. Instr. 81, 073108 (2010). \\ 6) Europhys. Lett. 84, 37003 (2008). \\ 7) Phys. Rev. Lett. 101, 016403 (2008).
*Supported by the U.S. DOE through the LANL LDRD Program and the Office of Basic Energy Sciences, Division of Materials Sciences and Engineering.
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2013.MAR.Z1.4
The American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics.
1 Physics Ellipse, College Park, MD 20740-3844
Editorial Office 1 Research Road, Ridge, NY 11961-2701 (631) 591-4000
Office of Public Affairs 529 14th St NW, Suite 1050, Washington, D.C. 20045-2001 (202) 662-8700