Ofer Yuli

Scanning tunneling spectroscopy of SmFeAsO 0.85 : Possible evidence for d -wave order-parameter symmetry

Scanning tunneling microscopy and scanning tunneling spectroscopy (STS) have been examined for an Al nanocluster periodic array grown on p-type silicon substrate. Local density of states at Al and Si sites within the nanocluster has been extracted from site-resolved STS spectra by taking into account tip-induced band bending (TIBB) effect. Besides, it has been clarified that the surface-potential- energy shift caused by TIBB effect directly influences the tunneling current spectra. Consequently, a good correspondence has been found between the experimental spectra and the theoretical local density of states except for the energy gap. The energy gap has been experimentally determined as 1.7 eV, which is much larger than the predicted value. This discrepancy could be ascribed to the local-density approximation rather than the TIBB effect.

Evidence for crossed Andreev reflections in bilayers of (100) YBa 2 Cu 3 O 7 − δ and the itinerant ferromagnet SrRuO 3

Scanning tunneling spectroscopy measurements on thin epitaxial SrRuO3/(100)YBCO ferromagnet/superconductor bilayers, reveal localized regions in which the superconductor order parameter penetrates the ferromagnet to more than 26 nm, an order of magnitude larger than the coherence length in the ferromagnetic layer. These regions consist of narrow (< 10 nm) and long strips, separated by at least 200 nm, consistent with the known magnetic domain wall structure in SrRuO3. We attributed this behavior to Crossed Andreev Reflections, taking place in the vicinity of the magnetic domain walls.

Evidence for induced magnetization in superconductor-ferromagnet heterostructures: A scanning tunneling spectroscopy study

We performed scanning tunneling spectroscopy of

Penetration of Andreev bound states into the ferromagnet in a Sr Ru O 3 ∕ ( 110 ) Y Ba 2 Cu 3 O 7 − δ bilayer: A scanning tunneling spectroscopy study

c

Spatial modulation of midgap states in (001) La 1.88 Sr 0.12 CuO 4 films: Indications for antiphase ordering of the d -wave order parameter

-axis-oriented

Enhancement of the Superconducting Transition Temperature of La2-xSrxCUO4 Bilayers : Role of Pairing and Phase Stiffness

{\text{YBa}}_{2}{\text{Cu}}_{3}{\text{O}}_{7\ensuremath{-}\ensuremath{\delta}}

Possible evidence for anti-phase ordering of the d-wave order parameter from the spatial modulation of mid-gap states in (001)La1.88Sr0.12CuO4 films

films on top of which ferromagnetic

Evidence for Induced Magnetization in Superconductor/Ferromagnet Bilayers

{\text{SrRuO}}_{3}

Scanning tunneling spectroscopy characterization of the pseudogap and the x = 1 8 anomaly in La 2 − x Sr x Cu O 4 thin films

islands were grown epitaxially in situ. When measured on the ferromagnetic islands, the density of states exhibits small gaplike features consistent with the expected short-range penetration of the order parameter into the ferromagnet. However, anomalous split-gap structures are measured on the superconductor in the vicinity of ferromagnetic islands. This observation provides evidence for the recently predicted induced magnetization in the superconductor side of a superconductor/ferromagnet junction and demonstrates its manifestation in the density of states of the superconductor. Surprisingly, the length scale of the effect inside the superconductor was found to be an order of magnitude larger than the superconducting coherence length. This is inconsistent with the theoretical prediction of a penetration depth of only a few superconducting coherence lengths. We discuss a possible origin for this discrepancy.

Evidence for Crossed Andreev Reflection in (100)YBa2Cu3O7-δ-SrRuO3 superconductor-ferromagnet bilayers

Scanning tunneling spectroscopy of thin epitaxial