Gate Tunable Supercurrent in Josephson Junctions Based on Bi2Te3 Topological Insulator Thin Films

Abstract

We report transport measurements on Josephson junctions consisting of Bi2Te3 topological insulator (TI) thin films contacted by superconducting Nb electrodes. For a device with junction length L = 134 nm, the critical supercurrent Ic can be modulated by an electrical gate which tunes the carrier type and density of the TI film. Ic can reach a minimum when the TI is near the charge neutrality regime with the Fermi energy lying close to the Dirac point of the surface state. In the p-type regime the Josephson current can be well described by a short ballistic junction model. In the n-type regime the junction is ballistic at 0.7 K < T < 3.8 K while for T < 0.7 K the diffusive bulk modes emerge and contribute a larger Ic than the ballistic model. We attribute the lack of diffusive bulk modes in the p-type regime to the formation of p-n junctions. Our work provides new clues for search of Majorana zero mode in TI-based superconducting devices.

arXiv comment6 pages, 4 figures, The manuscript with the same title will be published by Chinese Physics Letters

References in corpus (23)

• Topological Insulators
• Topological insulators and superconductors
• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• New directions in the pursuit of Majorana fermions in solid state systems
• Josephson Current and Noise at a Superconductor-Quantum Spin Hall Insulator-Superconductor Junction
• Gate-Voltage Control of Chemical Potential and Weak Anti-localization in Bismuth Selenide
• Electrically detected interferometry of Majorana fermions in a topological insulator
• $4\pi$-periodic Josephson supercurrent in HgTe-based topological Josephson junctions
• Unconventional Josephson Effect in Hybrid Superconductor-Topological Insulator Devices
• Josephson supercurrent through a topological insulator surface state
• The Josephson critical current in a long mesoscopic S-N-S junction
• Ballistic Josephson junctions in edge-contacted graphene
• Quantum oscillations of the critical current and high-field superconducting proximity in ballistic graphene
• Quantum Hall Effect on Top and Bottom Surface States of Topological Insulator (Bi1-xSbx)2Te3 Films
• Topological Josephson ${\varphi }_0$-junctions
• Strong Superconducting Proximity Effect in Pb-Bi2Te3 Hybrid Structures
• Symmetry Protected Josephson Supercurrents in Three-Dimensional Topological Insulators
• Manipulation of Topological States and Bulk Band Gap Using Natural Heterostructures of a Topological Insulator
• Josephson supercurrent through the topological surface states of strained bulk HgTe
• Helical Andreev bound states and superconducting Klein tunneling in topological insulator Josephson junctions
• Current-phase relation for Josephson effect through helical metal
• Gate-tunable supercurrent and multiple Andreev reflections in a superconductor-topological insulator nanoribbon-superconductor hybrid device
• Josephson Effect and Charge Distribution in Thin Bi${}_2$Te${}_3$ Topological Insulators

Cited by in corpus (3)

• Quantum Transport and Potential of Topological States for Thermoelectricity in Bi${}_2$Te${}_3$ Thin Films
• Low-damage electron beam lithography for nanostructures on Bi${}_2$Te${}_3$-class topological insulator thin films
• Planar magnetic texture on the surface of a topological insulator