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Abstract The interface between 2D topological Dirac states and ans‐wave superconductor is expected to support Majorana‐bound states (MBS) that can be used for quantum computing applications. Realizing these novel states of matter and their applications requires control over superconductivity and spin‐orbit coupling to achieve spin‐momentum‐locked topological interface states (TIS) which are simultaneously superconducting. While signatures of MBS have been observed in the magnetic vortex cores of bulk FeTe0.55Se0.45, inhomogeneity and disorder from doping make these signatures unclear and inconsistent between vortices. Here superconductivity is reported in monolayer (ML) FeTe1–ySey(Fe(Te,Se)) grown on Bi2Te3by molecular beam epitaxy (MBE). Spin and angle‐resolved photoemission spectroscopy (SARPES) directly resolve the interfacial spin and electronic structure of Fe(Te,Se)/Bi2Te3heterostructures. Fory = 0.25, the Fe(Te,Se) electronic structure is found to overlap with the Bi2Te3TIS and the desired spin‐momentum locking is not observed. In contrast, fory = 0.1, reduced inhomogeneity measured by scanning tunneling microscopy (STM) and a smaller Fe(Te,Se) Fermi surface with clear spin‐momentum locking in the topological states are found. Hence, it is demonstrated that the Fe(Te,Se)/Bi2Te3system is a highly tunable platform for realizing MBS where reduced doping can improve characteristics important for Majorana interrogation and potential applications.
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Spin–momentum locking induced non-local voltage in topological insulator nanowire
The momentum and spin of charge carriers in the topological insulators are constrained to be perpendicular to each other due to the strong spin–orbit coupling. We have investigated this unique spin–momentum locking property in Sb 2 Te 3 topological insulator nanowires by injecting spin-polarized electrons through magnetic tunnel junction electrodes. Non-local voltage measurements exhibit an asymmetry with respect to the magnetic field applied perpendicular to the nanowire channel, which is remarkably different from that of a non-local measurement in a channel that lacks spin–momentum locking. In stark contrast to conventional non-local spin valves, simultaneous reversal of magnetic moments of all magnetic contacts to the Sb 2 Te 3 nanowire alters the non-local voltage. This unusual asymmetry is a clear signature of the spin–momentum locking in the Sb 2 Te 3 nanowire surface states.
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- PAR ID:
- 10251569
- Date Published:
- Journal Name:
- Nanoscale
- Volume:
- 12
- Issue:
- 45
- ISSN:
- 2040-3364
- Page Range / eLocation ID:
- 22958 to 22962
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/d0nr06590k
