Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userTemperature and magnetic field dependent tunneling spectroscopy of PtIr/Sr$_{0.9}$La$_{0.1}$CuO$_2$ point contact
380
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
Low barrier quasiparticle tunneling spectroscopy on Sr$_{0.9}$La$_{0.1}$CuO$_2$ has been studied with PtIr/Sr$_{0.9}$La$_{0.1}$CuO$_2$ point contacts at various temperatures and magnetic fields. No zero-bias conductance peaks are observed. By fitting tunneling conductance to Blonder-Tinkham-Klapwijk theory, the temperature dependent s-wave superconducting gaps are obtained. The present results exclude the possibility of d-wave symmetry for the pair gap in Sr$_{0.9}$La$_{0.1}$CuO$_2$, and do not support the conventional phonon mediated pairing in this system either.
rate research
Read More
We report on the spectra of point-contacts made on Sr$_{0.88}$La$_{0.12}$CuO$_2$ thin films. Besides a clear evidence for the superconducting gap, we discuss the origin of specific features, such as resistance peaks at the gap voltage and the occurrence of a two-steps resistance decrease.
We present point-contact spectroscopy data for junctions between a normal metal and the newly discovered F-doped superconductor LaO$_{0.9}$F$_{0.1-delta}$FeAs (F-LaOFeAs). A zero-bias conductance peak was observed and its shape and magnitude suggests the presence of Andreev bound states at the surface of F-LaOFeAs, which provides a possible evidence of an unconventional pairing symmetry with a nodal gap function. The maximum gap value $Delta_0approx3.9pm0.7$meV was determined from the measured spectra, in good agreement with the recent experiments on specific heat and lower critical field.
We study superconducting properties in multilayer thin films consisting of superconducting La$_{1.85}$Sr$_{0.15}$CuO$_4$ (LSCO) and Mott insulator Sr$_2$IrO$_4$ (SIO) and report enhanced superconductivity in optimized sample. These multilayer heterostructures show an increase in superconducting transition temperature ($T_C$) as compared to the single layer LSCO films. The temperature dependence of SIO single layer is also investigated under thermal activation, Arrhenius-type behaviour, and variable-range hopping mechanisms for different temperature regimes. The decrease in $T_C$ beyond an optimum thickness of LSCO in these multilayers is analyzed in the framework of a model based on the assumption of induced superconductivity in SIO-LSCO interface due to the doping of La and/or oxygen deficiencies into SIO layers
Neutron diffraction has been a very prominent tool to investigate high-temperature superconductors, in particular through the discovery of an incommensurate magnetic signal known as stripes. We here report the findings of a neutron diffraction experiment on the superconductor (La,Sr)$_2$CuO$_4$, where a spurious signal appeared to be magnetic stripes. The signal strength was found to be strongly dependent on the neutron energy, peaking at $E = 4.6$~meV. We therefore attribute the origin of this signal to be a combination of multiple scattering and crystal twinning. A forward calculation of the scattering intensity including these two effects almost completely recovers our experimental observations. We emphasise the need for employing such analysis when searching for ways to avoid spurious scattering signals.
High-$T_{rm{c}}$ cuprate superconductors host spin, charge and lattice instabilities. In particular, in the antiferromagnetic glass phase, over a large doping range, lanthanum based cuprates display a glass-like spin freezing with antiferromagnetic correlations. Previously, sound velocity anomalies in La$_{2-x}$Sr$_{x}$CuO$_4$ (LSCO) for hole doping $pgeq 0.145$ were reported and interpreted as arising from a coupling of the lattice to the magnetic glass [Frachet, Vinograd et al., Nat. Phys. 16, 1064-1068 (2020)]. Here we report both sound velocity and attenuation in LSCO $p=0.12$, i.e. at a doping level for which the spin freezing temperature is the highest. Using high magnetic fields and comparing with nuclear magnetic resonance (NMR) measurements, we confirm that the anomalies in the low temperature ultrasound properties of LSCO are produced by a coupling between the lattice and the spin glass. Moreover, we show that both sound velocity and attenuation can be simultaneously accounted for by a simple phenomenological model originally developed for canonical spin glasses. Our results point towards a strong competition between superconductivity and spin freezing, tuned by the magnetic field. A comparison of different acoustic modes suggests that the slow spin fluctuations have a nematic character.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
