Two-component energy spectrum of cuprates in the pseudogap phase and its evolution with temperature and at charge ordering

Abstract

In the search for mechanisms of high-temperature superconductivity it is critical to know the electronic spectrum in the pseudogap phase from which superconductivity evolves. The lack of angle-resolved photoemission data for every cuprate family precludes an agreement as to its structure, doping and temperature dependence and the role of charge ordering. Here we show that, in the entire Fermi-liquid-like regime that is ubiquitous in underdoped cuprates, the spectrum consists of holes on the Fermi arcs and an electronic pocket. We argue that experiments on the Hall coefficient identify the latter as a permanent feature at doped hole concentration x > 0.08–0.10, in contrast to the idea of the Fermi surface reconstruction via charge ordering. The longstanding issue of the origin of the negative Hall coefficient in YBCO and Hg1201 at low temperature is resolved: the electronic contribution prevails as mobility of the latter (evaluated by the Dingle temperature) becomes temperature independent, while the mobility of holes scattered by the short-wavelength charge density waves decreases.

Evidence for a universal Fermi-liquid scattering rate throughout the phase diagram of the copper-oxide superconductors

“…Since the universal magnitude and temperature dependence of the scattering rate directly connect the PG/FL, SM, and overdoped FL regions without any changes at T * and T ** , the archetypal linear temperature dependence of the resistivity may not reflect a linear scattering rate, contrary to common belief [1]. Instead, the ρ ∝ T behavior appears to be the result of a temperature-dependent carrier density, consistent with the well-known approximate 1/R H ∝ T behavior for T>T * [5,18,39]. In fact, a change in carrier density must always be associated with the formation of a gap, and the PG cannot be an exception.…”

“…We note that calculations indicate that direct oxygen-oxygen propagation may generate arcs with sizeable oxygen spectral weight at the Fermi level [17,38]. Moreover, umklapp interactions might be essential to obtain the T 2 scattering rate [4,17,18]. Regardless of the ultimate microscopic description, the transport results presented here imply that the transformation from a state with a hole density of (1+p)/V to a state with a density of p/V holes is complete at T ** [49,50].…”

“…A simple estimate of the carrier density from the arc length in the PG/FL regime indeed suggests that the density is low and increases with doping (≈p) [4]. More rigorous theoretical modeling yields the same conclusion [18,38]. The Hall data, including the present result, are overall consistent with a gradual evolution from p carriers that reside on arcs at temperatures below T ** toward a full Fermi surface of size 1+p not only at large doping levels [3], but also at high temperatures [5,39] (see also appendixes F and G).…”

Superconductivity in Quantum Complex Matter: the Superstripes Landscape

“…It is now clear for that the inclusion of lattice instabilities of perovskites [118] and the anisotropic strain [119] is needed to understand the anisotropic multi gap superconductivity in strongly correlated systems. Moreover, today there is a high interest on electron-phonon interaction [43,95] and on lattice heterogeneity as proposed by Alex [120]. A new rapidly developing field is at the crossing point between the research a) on mixed boson-fermion systems in ultracold gases [121] b) shape resonances in multigap superconductivity near Lifshitz transitions in complex heterostructures and c) percolation of filamentary superconductivity in a granular landscape showing mesoscale correlated disorder [105][106] after the accumulated information on complex spatial distribution of defects, strain fluctuations, SDW puddles [122] after many works made in these last ten years [123][124][125][126][127].…”

Complex Lattice and Charge Inhomogeneity Favoring Quantum Coherence in High-Temperature Superconductors

“…In the formation of the superconducting condensates [13][14][15] The spatial complexity emerges in these systems since by tuning the chemical potential near a Lifshitz transition the electronic system made by strongly interacting particles is predicted to undergo phase separation [25,26] which can be frustrated by a long range Coulomb interaction giving a multiscale phase separation going from the nanoscale to the micron scale spanning the mesoscale spatial range between the atomic and macroscopic space. In fact phase separation has been observed in cuprates and related materials [27][28][29][30][31][32] and it has been related with exotic theories of high temperature superconductivity [33][34][35][36][37][38][39][40][41][42][43] The complex electronic and structural landscape of the strongly correlated electronic structure of the quasi 2D copper oxide plane in cuprate superconductors, was first unveiled by XANES spectroscopy using synchrotron radiation [44][45][46][47][48]. It has provided first, the evidence of the orbital character of the itinerant holes (in the oxygen 2p orbital) [49] and second, the coexistence of two electronic states at the Fermi level: polarons [50] (where the ratio between the pairing interaction and the local Fermi energy is close to one) around the antinodal point and free quasi-particles around the nodal point of the Brillouin zone.…”