Two-dimensional electron liquid state at LaAlO_3-SrTiO_3 interfaces (2009)
Breitschaft, M., Tinkl, V., Pavlenko, N., Thiel, S., Richter, C., Kirtley, J. R., ...
Interfaces between oxides have recently been found to generate two-dimensional electron gases, much as interfaces between standard semiconductors do. The interface between LaAlO3 and SrTiO3 is...
Electric Field Control of the LaAlO$_{3}$/SrTiO$_{3}$ Interface Ground State (2008)
Caviglia, A. D., Gariglio, S., Reyren, N., Jaccard, D., Schneider, T., Gabay, M., ...
Interfaces between complex oxides are emerging as one of the most interesting playgrounds in condensed matter physics. In this special setting, in which translational symmetry is artificially broken,...
Role of magnetic and orbital ordering at the metal-insulator transition in NdNiO3 (2006)
Scagnoli, V., Staub, U., Mulders, A. M., Janousch, M., Meijer, G. I., Hammerl, G., ...
Soft x-ray resonant scattering at the Ni L2,3 edges is used to test models of magnetic and orbital-ordering below the metal-insulator transition in NdNiO3. The large branching ratio of the L3 to L2...
Half - h/2e - Oscillations of SQUIDs (2004)
Schneider, C. W., Hammerl, G., Logvenov, G., Kopp, T., Kirtley, J. R., Hirschfeld, P. J., ...
The current-voltage characteristics of Superconducting Quantum Interference Devices (SQUIDs) are known to modulate as a function of applied magnetic field with a period of one flux quantum...
Robust dx2-y2 pairing symmetry in high-temperature superconductors (2004)
Tsuei, C. C., Kirtley, J. R., Hammerl, G., Mannhart, J., Raffy, H., Li, Z. Z.
Although initially quite controversial, it has been widely accepted that the Cooper pairs in optimally doped cuprate superconductors have predominantly dx2-y2 wavefunction symmetry. The controversy...
Comparison of YBCO and Ca-substituted YBCO thin films for microwave applications. (2004)
Seron, D., Oates, D.E., Anderson, A.C., Halbritter, J., Hammerl, G., Hein, M., ...
8th Symp.on High Temperature Superconductors in High-Frequency Fields, Begur, E, May 26-29, 2004
Electronic Transport through YBCO Grain Boundary Interfaces between 4.2 K and 300 K (2003)
Schneider, C. W., Hembacher, S., Hammerl, G., Held, R., Schmehl, A., Weber, A., ...
The current-induced dissipation in YBCO grain boundary tunnel junctions has been measured between 4.2 K and 300 K. It is found that the resistance of 45 degree (100)/(110) junctions decreases...
A possible solution of the grain boundary problem for applications of high-Tc superconductors (2002)
Hammerl, G., Herrnberger, A., Schmehl, A., Weber, A., Wiedenmann, K., Schneider, C. W., ...
It is shown that the critical current density of high-Tc wires can be greatly enhanced by using a threefold approach, which consists of grain alignment, doping, and optimization of the grain...
Large grain boundary area superconductors (2002)
Hammerl, G., Bielefeldt, H., Leitenmeier, S., Schmehl, A., Schneider, C. W., Weber, A., ...
For many applications of polycrystalline high-Tc superconductors the small critical currents of the grain boundaries pose a severe problem. To solve this problem we derive novel designs for the...
Coated conductors containing grains with big aspect ratios (2002)
Leitenmeier, S., Bielefeldt, H., Hammerl, G., Schmehl, A., Schneider, C. W., Mannhart, J.
It is shown that the critical currents of high-Tc superconducting tapes fabricated by the coated conductor technologies are enhanced considerably if grain arrangements with large effective grain...
Observation of splintered Josephson vortices at grain boundaries in YBa2Cu3O7-d (2002)
Mints, R.G., Papiashvili, I., Kirtley, J.R., Hilgenkamp, J.W.M., Hammerl, G., Mannhart, J.
We have directly observed well-separated Josephson vortex splinters with unquantized magnetic flux at asymmetric 45° grain boundaries in YBa2Cu3O7-¿ films by imaging magnetic flux with scanning...
Observation of splintered Josephson vortices at grain boundaries in YBa2Cu3O7-d (2002)
Mints, R.G., Papiashvili, I., Kirtley, Dr. J.R., Hilgenkamp, Prof. H., Hammerl, G., Mannhart, J.
We have directly observed well-separated Josephson vortex splinters with unquantized magnetic flux at asymmetric 45° grain boundaries in YBa2Cu3O7-¿ films by imaging magnetic flux with scanning...
Observation of splintered Josephson vortices at grain boundaries in YBa2Cu3O7-d (2002)
Mints, R.G., Papiashvili, I., Kirtley, J.R., Hilgenkamp, H., Hammerl, G., Mannhart, J.
We have directly observed well-separated Josephson vortex splinters with unquantized magnetic flux at asymmetric 45° grain boundaries in YBa2Cu3O7-¿ films by imaging magnetic flux with scanning...
Hammerl, G., Mannhart, J., Tajima, S., Yoshida, K., ...
Scanning tunneling spectroscopy (STS) studies reveal long-range (similar to 100 nm) spatial homogeneity in optimally and underdoped superconducting YBa2Cu3O7-delta (YBCO) single crystals and thin...
Evidence of doping-dependent pairing symmetry in cuprate superconductors (2001)
Hammerl, G., Mannhart, J., Schmehl, A., Schneider, C. W., ...
Scanning tunneling spectroscopy studies reveal long-range spatial homogeneity and predominantly d(x2)-(y2)-pairing spectral characteristics in under- and optimally doped YBa2Cu3O7-delta...
Evidence of Doping-Dependent Pairing Symmetry in Cuprate Superconductors (2001)
Hammerl, G., Mannhart, J., Schmehl, A., Schneider, C. W., ...
Scanning tunneling spectroscopy (STS) studies reveal long-range spatial homogeneity and predominantly $d_{x^2-y^2}$-pairing spectral characteristics in under- and optimally doped $\rm...
Hammerl, G., Mannhart, J., Tajima, S., Yoshida, K., ...
Scanning tunneling spectroscopy (STS) studies reveal long-range (~100 nm) spatial homogeneity in optimally and underdoped superconducting YBa_2Cu_3O_{7-\delta} (YBCO) single crystals and thin films,...
Doping-induced enhancement of grain boundary critical currents (2001)
Hammerl, G., Bielefeldt, H., Goetz, B., Schmehl, A., Schneider, C.W., Schulz, R.R., ...