Half-Integer Flux Quantization in a Superconducting Loop with a Ferromagnetic π-Junction
| Autor: | M. Aprili, C. Strunk, J. Bentner, M. L. Della Rocca, Andreas Bauer |
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| Přispěvatelé: | Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11) |
| Rok vydání: | 2007 |
| Předmět: |
Physics
Condensed matter physics Magnetic domain Magnetic energy Magnetic particle inspection 74.50.+r - 85.25.Cp equipment and supplies Condensed Matter::Mesoscopic Systems and Quantum Hall Effect Condensed Matter Physics 01 natural sciences Atomic and Molecular Physics and Optics 010305 fluids & plasmas Magnetic anisotropy Magnetization Remanence Condensed Matter::Superconductivity Magnetic flux quantum 0103 physical sciences [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci] General Materials Science 010306 general physics human activities Magnetic dipole |
| Zdroj: | Journal of Low Temperature Physics Journal of Low Temperature Physics, Springer Verlag (Germany), 2007, 147, pp.431-439. ⟨10.1007/s10909-007-9328-7⟩ |
| ISSN: | 1573-7357 0022-2291 |
| DOI: | 10.1007/s10909-007-9328-7 |
| Popis: | This work is dedicated to H. von Löhneysen on the occasion of his 60th birthday.; Superconducting loops containing a π-junction are predicted to show a spontaneous magnetic moment in zero external magnetic field. In order to confirm this longstanding prediction experimentally, we performed magnetization measurements on individual mesoscopic superconducting niobium loops with a ferromagnetic (PdNi) π-junction. The loops are prepared on top of the active area of a micro Hall-sensor based on high mobility GaAs/AlGaAs heterostructures. We observe switching of the loop between different magnetization states at very low-magnetic fields, which is asymmetric for positive and negative sweep direction. This is evidence for a spontaneous current induced by the intrinsic phase shift of the π-junction. In addition, the presence of the spontaneous current at zero applied field is directly revealed by an increase of the magnetic moment with decreasing temperature, which results in a half integer flux quantization in the loop at low temperatures. |
| Databáze: | OpenAIRE |
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