Superconducting quantum interference devices made of Sb-doped Bi2Se3 topological insulator nanoribbons

Abstract

We report the fabrication and characterization of superconducting quantum interference devices (SQUIDs) made of Sb-doped Bi 2 Se 3 topological insulator (TI) nanoribbon (NR) contacted with PbIn superconducting electrodes. When an external magnetic field was applied along the NR axis, the TI NR exhibited periodic magneto-conductance oscillations, the so-called Aharonov-Bohm oscillations, owing to one-dimensional subbands. Below the superconducting transition temperature of PbIn electrodes, we observed supercurrent flow through TI NR-based SQUID. The critical current periodically modulates with a magnetic field perpendicular to the SQUID loop, revealing that the periodicity corresponds to the superconducting flux quantum. Our experimental observations can be useful to explore Majorana bound states (MBS) in TI NR, promising for developing topological quantum information devices.

Adjustable Quantum Interference Oscillations in Sb-Doped Bi2Se3 Topological Insulator Nanoribbons

“…Meanwhile, the ensemble-averaged FFT spectrum can be used to identify the electrical transport regime of the TI NRs at an arbitrary disorder strength. We expect the channel-length-dependent topological quantum interferometers of the TI NR to be useful for investigating various features of topological quantum devices combined with superconductivity, , ferromagnetism, , or nanomechanics …”

Bulk-surface coupling in dual topological insulator Bi1Te1 and Sb-doped Bi1Te1 single crystals via electron-phonon interaction

“…So, one can expect Sb to replace Bi atoms due to their similarity in stable oxidation states. Since the ratio of ionic radii: r(Bi 3+ )/r(Sb 3+ ) ≈ 1.56, we expect no significant strain-induced change in topological properties in Sb-doped Bi 1 Te 1 , as evident from the symmetry mode analysis of the parent and undoped crystals [42][43][44]. Rather electrical transport described later, proves that Sb helps to reduce and compensate the unwanted bulk defects.…”

Current-phase relation of a short multi-mode Bi2Se3 topological insulator nanoribbon Josephson junction with ballistic transport modes

“…We have realized Josephson junctions using Bi 2 Se 3 nanobelts, grown by physical vapor deposition, which are at least 7-8 µm long to be able to fabricate both the test and reference junction on the same nanobelt [17,26]. The fabrication process involves the dry transfer of nanobelts to a SiO 2 /Si substrate followed by electron beam lithography and metallization.…”