Anomalous Criticality in the Electrical Resistivity of La _{2– x} Sr _x CuO ₄

Abstract

The presence or absence of a quantum critical point and its location in the phase diagram of high-temperature superconductors have been subjects of intense scrutiny. Clear evidence for quantum criticality, particularly in the transport properties, has proved elusive because the important low-temperature region is masked by the onset of superconductivity. We present measurements of the low-temperature in-plane resistivity of several highly doped La2-xSrxCuO4 single crystals in which the superconductivity had been stripped away by using high magnetic fields. In contrast to other quantum critical systems, the resistivity varies linearly with temperature over a wide doping range with a gradient that scales monotonically with the superconducting transition temperature. It is maximal at a critical doping level (pc) approximately 0.19 at which superconductivity is most robust. Moreover, its value at pc corresponds to the onset of quasi-particle incoherence along specific momentum directions, implying that the interaction that first promotes high-temperature superconductivity may ultimately destroy the very quasi-particle states involved in the superconducting pairing.

Broken rotational symmetry on the Fermi surface of a high-Tc superconductor

“…54 This includes the linear-intemperature zero-field resistivity above the pseudogap temperature. [55][56][57] One possibility is that high magnetic fields suppress the pseudogap and restore the entire Fermi surface to a Fermi-liquid state-the possible Fermi surface reconstruction presented in Fig. 3d, e would require such a scenario for the pocket near the anti-nodal region to be ungapped.…”

Role of the van Hove singularity in the quantum criticality of the Hubbard model

“…The linear resistivity in the marginal Fermi liquid region is consistent with experiments. [44][45][46][47] For n = 0.75, both t ′ = 0 and t ′ /t = −0.1 show Fermi liquid character, with a resistivity which goes to zero quadratically when T approaches zero. The fact that doping region with marginal Fermi liquid character increases with negative t ′ has consequences for the phase diagram near the quantum critical point, which we will discuss in Section IV.…”

“…42,43 Above the quantum critical point, in a range of doping associated with marginal Fermi liq-uid behavior, the in-plane resistivity is known to vary linearly with T over a wide range of temperatures. [44][45][46][47][48][49][50] In the Fermi liquid region the low temperature resistivity varies as T 2 . The resistivity increases as the doping decreases from the Fermi liquid into the pseudogap region.…”

Black branes in flux compactifications

“…Now we also study the theory section 3.2 with a single Kähler-modulus and look for an electrically charged AdS 2 × R 2 solution. Absent magnetic charges, the axions are stabilized at their supersymmetric values, so we only need to consider the Kähler modulus v = e φ and dilaton D. The near horizon values are found to be 8) JHEP10 (2013)126 which have the same parametric dependence on the fluxes as the supersymmetric vacua (3.4). Recall thatẽ 1 ∼ N 1 in the large flux limit where we have perturbative control.…”

“…This has created a new area of research at the interface of condensed matter and high energy physics, with powerful methods that can be applied to systems of strongly interacting fermions [4][5][6][7] . This is especially important given the discovery of new materials, such as high T c superconductors and heavy fermion metals [8][9][10], which require going beyond the Fermi liquid paradigm.…”