Unconventional supercurrent phase in Ising superconductor Josephson junction with atomically thin magnetic insulator
Autor: | Daisuke Shindo, Na Hyun Jo, Loi T. Nguyen, Young Jae Shin, Robert J. Cava, Paul C. Canfield, K. Harada, Önder Gül, Hiroshi Idzuchi, K.-F. Huang, Falko Pientka, Philip Kim |
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Jazyk: | angličtina |
Rok vydání: | 2021 |
Předmět: |
Josephson effect
Physics Superconductivity Multidisciplinary Spintronics Condensed matter physics Science Supercurrent General Physics and Astronomy General Chemistry General Biochemistry Genetics and Molecular Biology law.invention SQUID law Condensed Matter::Superconductivity Ising model Condensed Matter::Strongly Correlated Electrons Cooper pair Quantum tunnelling |
Zdroj: | Nature Communications, Vol 12, Iss 1, Pp 1-8 (2021) |
ISSN: | 2041-1723 |
Popis: | In two-dimensional (2D) NbSe2 crystal, which lacks inversion symmetry, strong spin-orbit coupling aligns the spins of Cooper pairs to the orbital valleys, forming Ising Cooper pairs (ICPs). The unusual spin texture of ICPs can be further modulated by introducing magnetic exchange. Here, we report unconventional supercurrent phase in van der Waals heterostructure Josephson junctions (JJs) that couples NbSe2 ICPs across an atomically thin magnetic insulator (MI) Cr2Ge2Te6. By constructing a superconducting quantum interference device (SQUID), we measure the phase of the transferred Cooper pairs in the MI JJ. We demonstrate a doubly degenerate nontrivial JJ phase (ϕ), formed by momentum-conserving tunneling of ICPs across magnetic domains in the barrier. The doubly degenerate ground states in MI JJs provide a two-level quantum system that can be utilized as a new dissipationless component for superconducting quantum devices. Our work boosts the study of various superconducting states with spin-orbit coupling, opening up an avenue to designing new superconducting phase-controlled quantum electronic devices. Van der Waals structures provide a new platform to explore novel physics of superconductor/ferromagnet interfaces. Here, NbSe2 Josephson junction with Cr2Ge2Te6 enables non-trivial Josephson phase by spin-dependent interaction, boosting the study of superconducting states with spin-orbit coupling and phase-controlled quantum electronic device. |
Databáze: | OpenAIRE |
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