Two-dimensional superconductivity at the interface of a Bi2Te3/FeTe heterostructure

Qing Lin He; Hongchao Liu; Mingquan He; Ying Hoi Lai; Hongtao He; Gan Wang; Kam Tuen Law; Rolf Lortz; Jiannong Wang; Iam Keong Sou

doi:10.1038/ncomms5247

arXiv · 1309.6040

Two-dimensional superconductivity at the interface of a Bi2Te3/FeTe heterostructure

Qing Lin He·Hongchao Liu·Mingquan He·Ying Hoi Lai·Hongtao He·Gan Wang·Kam Tuen Law·Rolf Lortz·Jiannong Wang·Iam Keong Sou

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Abstract

Superconductivity at the interface of a heterostructure confined to nanometer-sized scale offers unique opportunities to study the exotic physics of two-dimensional superconductivity. The realization of superconductivity at the interface between a topological insulator and an iron-chalcogenide compound is highly attractive for exploring several recent theoretical predictions involving these two new classes of materials. Here, we report transport measurements on a Bi2Te3/FeTe heterostructure fabricated via van der Waals epitaxy, which demonstrate superconductivity at the interface induced by the Bi2Te3 epilayer with thickness even down to one quintuple layer. The two-dimensional nature of the observed superconductivity with the highest transition temperature around 12 K was verified by the existence of a Berezinsky-Kosterlitz-Thouless transition and the diverging ratio of in-plane to out-plane upper critical field on approaching the superconducting transition temperature. With the combination of interface superconductivity and Dirac surface states of Bi2Te3, the heterostructure studied in this work provides a novel platform for realizing Majorana fermions.

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Qing Lin He, Hongchao Liu, Mingquan He, Ying Hoi Lai, Hongtao He, Gan Wang, Kam Tuen Law, Rolf Lortz, Jiannong Wang, Iam Keong Sou. 2014-04-21. Two-dimensional superconductivity at the interface of a Bi2Te3/FeTe heterostructure. https://doi.org/10.1038/ncomms5247

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