English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

In this letter we report on the electrical transport properties ofBi$_4$Te$_3$ in a Josephson junction geometry using superconducting Alelectrodes with a Ti interdiffusion barrier. Bi$_4$Te$_3$ is proposed to be adual topological insulator, for which due to time-reversal and mirror symmetryboth a strong topological insulator phase as well as a crystalline topologicalphase co-exist. The formation of a supercurrent through the Bi$_4$Te$_3$ layeris explained by a two-step process. First, due to the close proximity of theAl/Ti electrodes a superconducting gap is induced within the Bi$_4$Te$_3$ layerright below the electrodes. The size of this gap is determined by analysingmultiple Andreev reflections (MARs) identified within the devices differentialresistance at low voltage biases. Second, based on the Andreev reflection andreverse Andreev reflection processes a supercurrent establishes in the weaklink region in between these two proximity coupled regions. Analyses of thetemperature dependency of both the critical current as well as MARs indicatemostly ballistic supercurrent contributions in between the proximitizedBi$_4$Te$_3$ regions even though the material is characterized by asemi-metallic bulk phase. The presence of these ballistic modes givesindications on the topological nature of Bi$_4$Te$_3$.

Ballistic surface channels in fully in situ defined Bi$_4$Te$_3$ Josephson junctions with aluminum contacts