title: Robust two-dimensional superconductivity and vortex system in Bi2Te3/FeTe heterostructures.
abstract: The discovery of two-dimensional superconductivity in Bi2Te3/FeTe heterostructures provides a new platform for the search of Majorana fermions in condensed matter systems. Since Majorana fermions are expected to reside at the core of the vortices, a close examination of the vortex dynamics in superconducting interface is of paramount importance. Here, we report the robustness of the interfacial superconductivity and 2D vortex dynamics in four as-grown and aged Bi2Te3/FeTe heterostructure with different Bi2Te3 epilayer thickness (3, 5, 7, 14 nm). After two years' air exposure, superconductivity remains robust even when the thickness of Bi2Te3 epilayer is down to 3 nm. Meanwhile, a new feature at ~13 K is induced in the aged samples, and the high field studies reveal its relevance to superconductivity. The resistance of all as-grown and aged heterostructures, just below the superconducting transition temperature follows the Arrhenius relation, indicating the thermally activated flux flow behavior at the interface of Bi2Te3 and FeTe. Moreover, the activation energy exhibits a logarithmic dependence on the magnetic field, providing a compelling evidence for the 2D vortex dynamics in this novel system. The weak disorder associated with aging-induced Te vacancies is possibly responsible for these observed phenomena.
authors.affiliation: Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.|Department of Physics, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
authors.forename: Hong-Chao
authors.initials: HC
authors.lastname: Liu
authors.affiliation: Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: William Mong Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
authors.forename: Qing Lin
authors.initials: QL
authors.lastname: He
authors.affiliation: Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.|William Mong Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
authors.forename: Iam Keong
authors.initials: IK
authors.lastname: Sou
authors.affiliation: Department of Physics, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
authors.forename: Swee K
authors.initials: SK
authors.lastname: Goh
authors.affiliation: Department of Physics, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.|William Mong Institute of Nano Science and Technology, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
authors.forename: Jiannong
authors.initials: J
authors.lastname: Wang