TY  - JOUR
A1  - Idzuchi, Hiroshi
A1  - Pientka, Falko
A1  - Huang, Katie F.
A1  - Harada, Ken
A1  - Gül, Önder
A1  - Shin, Young Jae
A1  - Nguyen, Loi T.
A1  - Jo, Na Hyun
A1  - Shindo, Daisuke
A1  - Cava, Robert J.
A1  - Canfield, Paul C.
A1  - Kim, Philip
T1  - Unconventional supercurrent phase in Ising superconductor Josephson junction with atomically thin magnetic insulator
T2  - Nature Communications
N2  - 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.
KW  - Spintronics
KW  - Superconducting properties and materials
KW  - Two-dimensional materials
Y1  - 2021
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/63250
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-632503
SN  - 2041-1723
N1  - The major part of the experiment performed by H.I. was supported by ARO (W911NF-17-1-0574) and measurement performed by K.F.H. was supported by NSF (QII-TAQS MPS 1936263). The sample fabrication was supported by DOE QPress (DE-SC0019300). P.K. acknowledges support from the DoD Vannevar Bush Faculty Fellowship N00014-18-1-2877. H.I. acknowledges JSPS Overseas Research Fellowship and the Nakajima Foundation for support. L.T.N. and R.J.C. acknowledge the US Department of Energy, Division of Basic Energy Sciences, grant DE-FG02 98ER45706 for supporting the growth of the NbSe2 crystals. Work done at Ames Lab (P.C.C. and N.H.J.) was supported by the U.S. Department of Energy, Office of Basic Energy Science, Division of Materials Sciences and Engineering. Ames Laboratory is operated for the U.S. Department of Energy by Iowa State University under Contract No. DE-AC02-07CH11358. N.H.J. was supported by the Gordon and Betty Moore Foundation’s EPiQS Initiative through Grant GBMF4411.
VL  - 12
IS  - art. 5332
SP  - 1
EP  - 8
PB  - Nature Publishing Group UK
CY  - [London]
ER  -