Quasiparticles in the pseudogap phase of underdoped cuprateKai-Yu Yang1, 2, H.-B. Yang3, P. D. Johnson3, T. M. Rice1, 2 and Fu-Chun Zhang2
1 Institut für Theoretische Physik, ETH Zürich - CH-8093 Zürich, Switzerland
2 Center for Theoretical and Computational Physics and Department of Physics, The University of Hong Kong Hong Kong SAR, China
3 Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory Upton, NY 11973, USA
received 10 January 2009; accepted in final form 8 April 2009; published May 2009
published online 11 May 2008
Recent angle-resolved photoemission (YANG H.-B. et al., Nature, 456 (2008) 77) and scanning tunneling microscopy (KOHSAKA Y. et al., Nature, 454 (2008) 1072) measurements on underdoped cuprates have yielded new spectroscopic information on quasiparticles in the pseudogap phase. New features of the normal state such as particle-hole asymmetry, maxima in the energy dispersion, and accompanying drops in the spectral weight of quasiparticles agree with the ansatz of Yang et al. for the single-particle propagator in the pseudogap phase. The coherent quasiparticle dispersion and reduced asymmetry in the tunneling density of states in the superconducting state can also be described by this propagator.
74.72.-h - Cuprate superconductors (high-Tc and insulating parent compounds).
74.20.Mn - Nonconventional mechanisms (spin fluctuations, polarons and bipolarons, resonating valence bond model, anyon mechanism, marginal Fermi liquid, Luttinger liquid, etc.).
79.60.-i - Photoemission and photoelectron spectra.
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