van der Waals π Josephson Junctions
| Autor: | Kaifei Kang, Helmuth Berger, Kenji Watanabe, Takashi Taniguchi, László Forró, Jie Shan, Kin Fai Mak |
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| Rok vydání: | 2022 |
| Předmět: |
van der waals josephson junctions
Condensed Matter - Mesoscale and Nanoscale Physics 0-pi transition superconductivity Mechanical Engineering Condensed Matter - Superconductivity FOS: Physical sciences Bioengineering General Chemistry Condensed Matter Physics Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ferromagnetism Superconductivity (cond-mat.supr-con) pi josephson junctions ferromagnetic josephson junctions Condensed Matter::Superconductivity Mesoscale and Nanoscale Physics (cond-mat.mes-hall) General Materials Science |
| Zdroj: | Nano letters. 22(13) |
| ISSN: | 1530-6992 |
| Popis: | Proximity-induced superconductivity in a ferromagnet can induce Cooper pairs with a finite center-of-mass momentum. The resultant spatially modulated superconducting order parameter is able to stabilize Josephson junctions (JJs) with pi phase difference in superconductor-ferromagnet heterostructures and realize 'quiet' phase qubits. The emergence of two-dimensional (2D) layered superconducting and magnetic materials promises a new platform for realizing pi JJs with atomically sharp interfaces by van der Waals stacking. Here we demonstrate a thickness-driven 0-pi transition in JJs made of NbSe2 (an Ising superconductor) with a Cr2Ge2Te6 (a ferromagnetic semiconductor) weak link. By systematically varying the Cr2Ge2Te6 thickness, we observe a vanishing supercurrent at a critical thickness around 8 nm, followed by a re-entrant supercurrent upon further increase in thickness. Near the critical thickness, we further observe unusual supercurrent interference patterns with vanishing critical current around zero in-plane magnetic field. They signify the formation of 0-pi JJs (with both 0 and pi regions) likely induced by the nanoscale magnetic domains in Cr2Ge2Te6. Our work highlights the potential of van der Waals superconductor-ferromagnet heterostructures for the explorations of unconventional superconductivity and superconducting electronics. Comment: none |
| Databáze: | OpenAIRE |
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