Related papers: Paramagnetic effect in YBaCuO grain boundary junct…
The response of YBCO bicrystal grain-boundary junctions to small dc magnetic fields (0 - 10 Oe) has been probed with a low-power microwave (rf) signal of 4.4 GHz in a microwave-resonator setup. Peaks in the microwave loss at certain dc…
Many experiments on high-temperature superconductors have shown paramagnetic behavior when the sample is field cooled. The paramagnetism was first attributed to a d-wave order parameter creating pi-junctions in the samples. However, the…
The spontaneously generated magnetic flux observed by Mannhart et. al. (1996) in 45 degree grain boundaries in YBCO was explained by them in terms of a d-wave superconducting order parameter and grain boundary faceting. This article argues…
[100]-tilt grain-boundary YBa2Cu3O7-x (YBCO) junctions are promising for investigation of macroscopic quantum phenomena in high-Tc Josephson junctions. However, fabrication of the [100]-tilt grain-boundary YBCO junctions with a high…
Recent experiments on high-temperature superconductors show paramagnetic behavior localized at grain boundaries (GB). This paramagnetism can be attributed to the presence unconventional d-wave induced $\pi$-junctions. By modeling the GB as…
The experimental results on the magnetic response of YBCO single crystals with unidirectional twin boundary planes in low magnetic fields (0.01 - 1 Oe) are discussed. The observed non-monotone temperature dependence of magnetization is…
We have performed a detailed study of the tunneling spectra of bicrystal grain boundary junctions (GBJs) fabricated from the HTS YBCO, BSCCO, LSCO, and NCCO. In all experiments the tunneling direction was along the CuO planes. With the…
We observe a zero-bias conductance peak (ZBCP) in the ab-plane quasiparticle tunneling spectra of thin film grain-boundary Josephson junctions made of the electron doped cuprate superconductor LaCeCuO. An applied magnetic field reduces the…
We examine the magnetic interference patterns of Josephson junctions with a region of 0- and of pi-phase shift. Such junctions have recently been realized as c-axis YBCO-Pb junctions with a single twin boundary in YBCO. We show that in…
We review the recent measurements of the current-phase relation in cuprate Josephson junctions. Special attention is paid to 45 degree grain boundary junctions and to c-axis junctions between YBCO and Nb. It is shown that the anomalous…
We have measured the current-phase relationship (CPR) of symmetric 45 degree YBaCuO grain boundary Josephson junctions. Substantial deviations of the CPR from conventional tunnel-junction behavior have been observed: (i) The critical…
The magneto-conductance in YBCO grain boundary Josephson junctions, displays fluctuations at low temperatures of mesoscopic origin. The morphology of the junction suggests that transport occurs in narrow channels across the grain boundary…
We theoretically investigate the anomalous and diode Josephson effects in planar two-dimensional Josephson junctions with arbitrarily oriented exchange fields in two ferromagnets within the barrier, and spin-orbit coupling at the…
We propose and implement a direct experimental test for subdominant superconducting phases with broken time-reversal symmetry in d-wave superconductors. The critical current of 45-degree asymmetric grain boundary junctions are shown to be…
We consider Josephson junctions formed by coupling two conventional superconductors via an unconventional magnet and investigate the formation of Andreev bound states, their impact on the Josephson effect, and the emergent superconducting…
Magneto-fluctuations of the normal resistance R_N have been reproducibly observed in high critical temp erature superconductor (HTS) grain boundary junctions, at low temperatures. We attribute them to mesoscopic transport in narrow channels…
Josephson junctions were photogenerated in underdoped thin films of the YBa$_2$Cu$_3$O$_{6+x}$ family using a near-field scanning optical microscope. The observation of the Josephson effect for separations as large as 100 nm between two…
We analyze the dc Josephson effect in a ballistic superconductor/ferromagnet/superconductor junction by means of the Bogoliubov-de Gennes equations in the quasiclassical Andreev approximation. We consider the possibility of ferromagnetism…
We have measured a paramagnetic Meissner effect in Nb-Al2O3-Nb Josephson junction arrays using a scanning SQUID microscope. The arrays exhibit diamagnetism for some cooling fields and paramagnetism for other cooling fields. The measured…
It has been predicted that the zero frequency density of states of YBCO in the superconducting phase can display interesting anisotropy effects when a magnetic field is applied parallel to the copper-oxide planes, due to the diamagnetic…