We investigate the manifestation of stripes in the in-plane resistivity anisotropy in untwinned single crystals of La2−xSrxCuO4 (x = 0.02-0.04) and YBa2Cu3Oy (y = 6.35-7.0). It is found that both systems show strongly temperature-dependent in-plane anisotropy in the lightly hole-doped region and that the anisotropy in YBa2Cu3Oy grows with decreasing y below ∼6.60 despite the decreasing orthorhombicity, which gives most direct evidence that electrons self-organize into a macroscopically anisotropic state. The transport is found to be easier along the direction of the spin stripes already reported, demonstrating that the stripes are intrinsically conducting in cuprates.PACS numbers: 74.25. Fy, 74.25.Dw, 74.20.Mn, 74.72.Dn, 74.72.Bk The mechanism of the high-temperature superconductivity is not settled 15 years after its discovery, mostly because it is unclear how best to describe the stronglycorrelated electrons in the high-T c cuprates. It has recently been discussed [1][2][3][4][5][6][7][8][9][10][11][12][13][14] that the electrons in cuprates self-organize into quasi-one-dimensional stripes, which might bring a paradigm shift in our way of understanding the two-dimensional (2D) electronic system in the cuprates. Though the self-organization is interesting in itself, the conventional wisdom suggests that the stripes are destructive to the superconductivity, because charge ordering would normally lead to an insulating state. However, there are intriguing theoretical proposals [10][11][12] that stripes can instead be responsible for the occurrence of the high-temperature superconductivity if they are conducting and meandering -properties that have never been clearly demonstrated before.In this Letter, we report novel in-plane transport anisotropy in the cuprates, which gives direct evidence for the conducting charge stripes in these materials; the temperature dependence and the magnitude of the anisotropy strongly suggest the stripes to be meandering and forming an electronic liquid crystal [11]. The evidence is shown for two representative materials of the high-temperature superconductors, La 2−x Sr x CuO 4 (LSCO) and YBa 2 Cu 3 O y (YBCO), highlighting the universality of the charge-stripe phenomenon in the cuprates. Most notably, the data for YBCO indicate that the charge stripes govern the transport in samples with T c of as high as 50 K, demonstrating that theories of high-temperature superconductivity should inevitably consider the self-organization of the electrons as an integral part.It is fair to say that the majority of the researchers today believe that the stripes are irrelevant to the superconductivity. This general belief comes not only from the conventional wisdom mentioned above but also from the current experimental situation, which can be summarized as follows: (i) strong evidence for the charge stripe order has been reported [1] only for Nd-doped LSCO, where the superconductivity is strongly suppressed; (ii) in other superconducting cuprates, evidence [2][3][4][5][6][7] is reasonably strong f...
We propose that resistivity curvature mapping (RCM) based on the in-plane resistivity data is a useful way to objectively draw electronic phase diagrams of high-Tc cuprates, where various crossovers are important. In particular, the pseudogap crossover line can be conveniently determined by RCM. We show experimental phase diagrams obtained by RCM for Bi2Sr2-zLazCuO6+delta, La2-xSrxCuO4, and YBa2Cu3Oy, and demonstrate the universal nature of the pseudogap crossover. Intriguingly, the electronic crossover near optimum doping depicted by RCM appears to occur rather abruptly, suggesting that the quantum-critical regime, if it exists, must be very narrow.
In the cuprate superconductors, Nernst and torque magnetization experiments have provided evidence that the disappearance of the Meissner effect at Tc is caused by the loss of long-range phase coherence, rather than the vanishing of the pair condensate. Here we report a series of torque magnetization measurements on single crystals of La2−xSrxCuO4 (LSCO), Bi2Sr2−yLayCuO6 (Bi 2201), Bi2Sr2CaCu2O 8+δ (Bi 2212) and optimal YBa2Cu3O7. Some of the measurements were taken to fields as high as 45 T. Focusing on the magnetization above Tc, we show that the diamagnetic term M d appears at an onset temperature T M onset high above Tc. We construct the phase diagram of both LSCO and Bi 2201 and show that T M onset agrees with the onset temperature of the vortex Nernst signal T ν onset . Our results provide thermodynamic evidence against a recent proposal that the high-temperature Nernst signal in LSCO arises from a quasiparticle contribution in a charge-ordered state.
Since the discovery of superconductivity at elevated temperatures in the copper oxide materials there has been a considerable effort to find universal trends and correlations amongst physical quantities, as a clue to the origin of the superconductivity. One of the earliest patterns that emerged was the linear scaling of the superfluid density (rho(s)) with the superconducting transition temperature (T(c)), which marks the onset of phase coherence. This is referred to as the Uemura relation, and it works reasonably well for the underdoped materials. It does not, however, describe optimally doped (where T(c) is a maximum) or overdoped materials. Similarly, an attempt to scale the superfluid density with the d.c. conductivity (sigma(dc)) was only partially successful. Here we report a simple scaling relation (rho(s) proportional, variant sigma(dc)T(c), with sigma(dc) measured at approximately T(c)) that holds for all tested high-T(c) materials. It holds regardless of doping level, nature of dopant (electrons versus holes), crystal structure and type of disorder, and direction (parallel or perpendicular to the copper-oxygen planes).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.