Controllable Rashba spin-orbit interaction in artificially engineered superlattices involving the heavy-fermion superconductor CeCoIn5.
By using a molecular beam epitaxy technique, we fabricate a new type of superconducting superlattices with controlled atomic layer thicknesses of alternating blocks between the heavy-fermion superconductor CeCoIn5, which exhibits a strong Pauli pair-breaking effect, and nonmagnetic metal YbCoIn5. The introduction of the thickness modulation of YbCoIn5 block layers breaks the inversion symmetry centered at the superconducting block of CeCoIn5. This configuration leads to dramatic changes in the temperature and angular dependence of the upper critical field, which can be understood by considering the effect of the Rashba spin-orbit interaction arising from the inversion symmetry breaking and the associated weakening of the Pauli pair-breaking effect. Since the degree of thickness modulation is a design feature of this type of superlattices, the Rashba interaction and the nature of pair breaking are largely tunable in these modulated superlattices with strong spin-orbit coupling.
Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
M
M
Shimozawa
Department of Physics, Kyoto University, Kyoto 606-8502, Japan and Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
S K
SK
Goh
Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
R
R
Endo
Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
R
R
Kobayashi
Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
T
T
Watashige
Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
Y
Y
Mizukami
Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
H
H
Ikeda
Department of Physics and Electronics, Osaka Prefecture University, Osaka 599-8531, Japan.
H
H
Shishido
Department of Physics, Niigata University, Niigata 950-2181, Japan.
Y
Y
Yanase
Research Center for Low Temperature and Materials Science, Kyoto University, Kyoto 606-8501, Japan.
T
T
Terashima
Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
T
T
Shibauchi
Department of Physics, Kyoto University, Kyoto 606-8502, Japan.
Y
Y
Matsuda