Superconductivity switched by spin-current and enhanced by forward-scattering interfacial phonons in heterostructure iron-based superconductor
ORAL
Abstract
Heterostructure iron-based superconductor made by self-assembly of FeAs monolayers atomically coupled with perovskite bilayers have attracted significant interest due to the possibilities of magnetic frustrations and existence of forward-scattering interfacial phonons. Using variable temperature and magnetic field spin-polarized scanning tunneling microscopy [1] and density-functional-theory calculations, we show that the magnetic symmetries in the Fe-layer of Sr2VO3FeAs are indeed metastable and as a result the superconductivity can be switched in nanometer-scale by changing the magnetic symmetry with spin-polarized or unpolarized tunneling current below the bulk Fe magnetic ordering temperature [2]. This may introduce possibilities of fast spintronic transistors controlling iron-based superconductivity. We also performed high-resolution quasiparticle interference (QPI) measurements and self-consistent BCS-theory-based QPI simulations to provide direct atomic-scale proofs of enhancement of iron-based superconductivity due to the BCS mechanism based on forward-scattering interfacial phonons [3].
[1] J.-O. Jung et al., Rev. Sci. Instrum. 88, 103702 (2017)
[2] J. Choi et al., Phys. Rev. Lett. (in print), arXiv:1707.01191
[3] J. Choi et al., Phys. Rev. Lett. 119, 107003 (2017)
[1] J.-O. Jung et al., Rev. Sci. Instrum. 88, 103702 (2017)
[2] J. Choi et al., Phys. Rev. Lett. (in print), arXiv:1707.01191
[3] J. Choi et al., Phys. Rev. Lett. 119, 107003 (2017)
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Presenters
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Jhinhwan Lee
- Physics, KAIST
- Korea Advanced Institute of Science and Technology
- Department of Physics, KAIST