title: Non-Fermi-liquid d-wave metal phase of strongly interacting electrons.
abstract: Developing a theoretical framework for conducting electronic fluids qualitatively distinct from those described by Landau's Fermi-liquid theory is of central importance to many outstanding problems in condensed matter physics. One such problem is that, above the transition temperature and near optimal doping, high-transition-temperature copper-oxide superconductors exhibit 'strange metal' behaviour that is inconsistent with being a traditional Landau Fermi liquid. Indeed, a microscopic theory of a strange-metal quantum phase could shed new light on the interesting low-temperature behaviour in the pseudogap regime and on the d-wave superconductor itself. Here we present a theory for a specific example of a strange metal--the 'd-wave metal'. Using variational wavefunctions, gauge theoretic arguments, and ultimately large-scale density matrix renormalization group calculations, we show that this remarkable quantum phase is the ground state of a reasonable microscopic Hamiltonian--the usual t-J model with electron kinetic energy t and two-spin exchange J supplemented with a frustrated electron 'ring-exchange' term, which we here examine extensively on the square lattice two-leg ladder. These findings constitute an explicit theoretical example of a genuine non-Fermi-liquid metal existing as the ground state of a realistic model.
authors.affiliation: Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106, USA.
authors.forename: Hong-Chen
authors.initials: HC
authors.lastname: Jiang
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Block
authors.forename: Ryan V
authors.initials: RV
authors.lastname: Mishmash
authors.forename: James R
authors.initials: JR
authors.lastname: Garrison
authors.forename: D N
authors.initials: DN
authors.lastname: Sheng
authors.forename: Olexei I
authors.initials: OI
authors.lastname: Motrunich
authors.forename: Matthew P A
authors.initials: MP
authors.lastname: Fisher