title: Spectroscopic evidence for Fermi liquid-like energy and temperature dependence of the relaxation rate in the pseudogap phase of the cuprates.
abstract: Cuprate high-Tc superconductors exhibit enigmatic behavior in the nonsuperconducting state. For carrier concentrations near "optimal doping" (with respect to the highest Tcs) the transport and spectroscopic properties are unlike those of a Landau-Fermi liquid. On the Mott-insulating side of the optimal carrier concentration, which corresponds to underdoping, a pseudogap removes quasi-particle spectral weight from parts of the Fermi surface and causes a breakup of the Fermi surface into disconnected nodal and antinodal sectors. Here, we show that the near-nodal excitations of underdoped cuprates obey Fermi liquid behavior. The lifetime τ(ω, T) of a quasi-particle depends on its energy ω as well as on the temperature T. For a Fermi liquid, 1/τ(ω, T) is expected to collapse on a universal function proportional to (ℏω)(2) + (pπk(B)T)(2). Magneto-transport experiments, which probe the properties in the limit ω = 0, have provided indications for the presence of a T(2) dependence of the dc (ω = 0) resistivity of different cuprate materials. However, Fermi liquid behavior is very much about the energy dependence of the lifetime, and this can only be addressed by spectroscopic techniques. Our optical experiments confirm the aforementioned universal ω- and T dependence of 1/τ(ω, T), with p ∼ 1.5. Our data thus provide a piece of evidence in favor of a Fermi liquid-like scenario of the pseudogap phase of the cuprates.
authors.affiliation: Département de Physique de la Matière Condensée, Université de Genève, 1211 Geneva, Switzerland.
authors.forename: Seyed Iman
authors.initials: SI
authors.lastname: Mirzaei
authors.forename: Damien
authors.initials: D
authors.lastname: Stricker
authors.forename: Jason N
authors.initials: JN
authors.lastname: Hancock
authors.forename: Christophe
authors.initials: C
authors.lastname: Berthod
authors.forename: Antoine
authors.initials: A
authors.lastname: Georges
authors.forename: Erik
authors.initials: E
authors.lastname: van Heumen
authors.forename: Mun K
authors.initials: MK
authors.lastname: Chan
authors.forename: Xudong
authors.initials: X
authors.lastname: Zhao
authors.forename: Yuan
authors.initials: Y
authors.lastname: Li
authors.forename: Martin
authors.initials: M
authors.lastname: Greven
authors.forename: Neven
authors.initials: N
authors.lastname: Barišić
authors.forename: Dirk
authors.initials: D
authors.lastname: van der Marel
references.citation: Phys Rev Lett. 2008 Feb 1;100(4):047004
references.pmid: 18352322
references.citation: Phys Rev Lett. 1993 Mar 29;70(13):2012-2015
references.pmid: 10053443
references.citation: Phys Rev Lett. 2011 Jul 29;107(5):056403
references.pmid: 21867083
references.citation: J Phys Condens Matter. 2011 Jul 27;23(29):293201
references.pmid: 21727309
references.citation: Proc Natl Acad Sci U S A. 2012 Nov 20;109(47):19161-5
references.pmid: 23115333
references.citation: Phys Rev Lett. 2002 Mar 4;88(9):097005
references.pmid: 11864047
references.citation: Phys Rev Lett. 2004 Dec 31;93(26 Pt 1):267001
references.pmid: 15698007
references.citation: Nature. 2007 May 31;447(7144):565-8
references.pmid: 17538614
references.citation: Phys Rev Lett. 2004 May 14;92(19):197001
references.pmid: 15169436
references.citation: Phys Rev Lett. 1995 Jul 3;75(1):105-108
references.pmid: 10059126
references.citation: Phys Rev B Condens Matter. 1991 Apr 1;43(10):7942-7954
references.pmid: 9996416