Related papers: Quantum size effects in ultra-thin YBa2Cu3O7-x fil…
Quantum geometry, a quantum mechanical quantity comprised of Berry curvature and quantum metric, describes the geometric structure of the electronic bands in solids. The correlation between nontrivial quantum geometry and quantum materials…
Electrons mediate many of the interactions between atoms in a solid. Their propagation in a material determines its thermal, electrical, optical, magnetic and transport properties. Therefore, the constant energy contours characterizing the…
We present a new measurement method which can be used to image gap nodal structure of superconductors whose pairing symmetry is under debate. This technique utilizes a high quality factor microwave resonance involving the sample of…
In cuprate high-temperature superconductors the doping level is fixed during synthesis, hence the charge carrier density per CuO$_2$ plane cannot be easily tuned by conventional gating, unlike in 2D materials. Strain engineering has…
In the present work we study the growth by pulsed laser deposition of YBa$_2$Cu$_3$O$_{7-\delta}$ (YBCO) films on the r-cut sapphire substrates. To improve the matching of the lattice parameters between the substrate and the film we use…
We analyze the thermoelectric response in layered metals with spontaneously broken rotation symmetry. We identify the anisotropy of the quasiparticle Nernst signal as an extremely sensitive probe of Fermi surface distortions characteristic…
The normal state in the hole underdoped copper oxide superconductors has proven to be a source of mystery for decades. The measurement of a small Fermi surface by quantum oscillations on suppression of superconductivity by high applied…
We have studied nodal tunneling into YBa2Cu3O7-x (YBCO) films under magnetic fields. The films' orientation was such that the CuO2 planes were perpendicular to the surface with the a and b axis at 450 form the normal. The magnetic field was…
Neutron crystal-field spectroscopy experiments in the Y- and La-type high-temperature superconductors HoBa2Cu3O6.56, HoBa2Cu4O8, and La1.81Sr0.15Ho0.04CuO4 are reviewed. By this bulk-sensitive technique, information on the gap function is…
The superconducting phase transition in YBa$_{2}$Cu$_{3}$O$_{7-\textit{$\delta $}}$(YBCO) thin film samples doped with non-superconducting nanodot impurities of CeO$_{2}$ are the focus of recent high-temperature superconductor studies.…
The point-contact (PC) spectra of the Andreev reflection dV/dI curves of the superconducting rare-earth nickel borocarbide ErNi2B2C (Tc=11 K) have been analyzed in the "one-gap" and "two-gap" approximations using the generalized…
The detection of quantum oscillations in the electrical resistivity of YBa2Cu3O6.5 provides direct evidence for the existence of Fermi surface pockets in an underdoped cuprate. We present a theoretical study of the electronic structure of…
We report on a systematic finite size scaling analysis of in-plane penetration depth data taken on Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ epitaxially-grown films and single crystals, and of in-plane and out of plane data taken on…
We present results on ultra low noise YBa$_2$Cu$_3$O$_{7-\delta}$ nano Superconducting QUantum Interference Devices (nanoSQUIDs). To realize such devices, we implemented high quality YBCO nanowires, working as weak links between two…
The anomalous decrease in microwave surface resistance, R_{s}, of superconducting YBa_{2}Cu_{3}O_{7-d} (YBCO) thin films in the presence of a low dc magnetic field is studied using a microstrip resonator technique. We have done a dc field…
We study superconductivity in isolated superconducting nano-cubes and nano-squares of size $L$ in the limit of negligible disorder, $\delta/\Delta_0 \ll 1$ and $k_F L \gg 1$ for which mean-field theory and semiclassical techniques are…
Recent experimental advances in surface science have made it possible to track the evolution of superconductivity in films as the thickness enters the nanoscale region where it is expected that the substrate plays an important role. Here,…
We study coherent quantum transport through a superconducting film connected to normal-metal electrodes. Simple expressions for the differential conductance and the local density of states are obtained in the clean limit and for transparent…
We argue that the results of recent scanning tunneling microscopy, angle-resolved photoemission and infrared spectroscopy experiments on the CuO chains of YBa$_2$Cu$_3$O$_{6+x}$ are consistently explained within a proximity model by the…
High temperature superconductors, especially YBa$_2$Cu$_3$O$_{7-\delta}$ (YBCO), are considered a key enabling technology towards a clean energy future. Hole doping in YBCO is a prerequisite for the emergence of its unchallenged…