High-Performance Bi₂Te₃-Based Topological Insulator Film Magnetic Field Detector

Abstract

Topological insulators with the nanoscaled metallic surface state (3-5 nm) are actually of typical functional nanostructures. Significant efforts have been devoted to study new families of topological insulators and identifications of topological surface state, as well as fundamental physics issues relating to spin-polarized surface electronic states in the past few years. However, transport investigations that can provide direct experimental evidence for potentially practical applications of topological insulators are limited, and realization of functional devices based on topological insulators is still under exploration. Here, using the Sn-doping Bi2Te3 polycrystalline topological insulator films, we fabricated high-performance current-controlled magnetic field detectors. When a parallel magnetic field is applied, the as-fabricated device exhibits a stable and reproducible magneto-resistance (MR) switching behavior, and the corresponding MR ratio can be modulated by the applied current. Even under such a low magnetic field (0.5 kG), the device still shows a distinguishable MR switching performance, suggesting that topological insulator devices are very sensitive to external stimulation and potentially applicable to weak magnetic field detection.

Crystal growth and characterization of bulk Sb2Te3 topological insulator

“…The presence of unique topological quantum states is confined by spin orbit interaction and time reversal symmetry, which prevents backscattering from impurities and defects [1][2][3][4][5][6][7][8][9][10][11][12]. In TIs the electrons are localized in the bulk but delocalized at the edges [13]. Furthermore, TIs behaves as excellent thermoelectric (TE) materials due to the presence of analogous material features such as heavy elements and narrow band gaps [12,13].…”

“…In TIs the electrons are localized in the bulk but delocalized at the edges [13]. Furthermore, TIs behaves as excellent thermoelectric (TE) materials due to the presence of analogous material features such as heavy elements and narrow band gaps [12,13].…”

“…In case of TIs, it is also interesting to note that a layered material exhibits rhombohedral structure with in R 3 m (D5) space group. Apart from being a known TI and TE, the Sb 2 Te 3 holds great promise as a phase changing material for information storage in chalcogenide alloys [18].Various synthesis techniques; such as Bridgman crystal growth, chemical vapour deposition (CVD), pulsed-laser deposition (PLD), flux free method, metal organic chemical vapour deposition (MOCVD), and molecular beam epitaxy (MBE) have been employed to grow bulk single crystals, thin films, nano-plates/nano-ribbons and nanosheets of TI and topological superconductor (TSC) materials [6,17,19,[26][27][28][29][30][31][32][33][34][35][36][37]. Interestingly, there are relatively less reports on the synthesis of bulk singly crystalline TI materials, using the flux free method.…”

Anomalous Photoelectric Effect of a Polycrystalline Topological Insulator Film

“…Thus far, there have not been any investigations of the interaction between light and polycrystalline TIs. Yet, high-quality polycrystalline TI Bi 2 (Te, Se) 3 thin films have been prepared through pulsed-laser deposition (PLD)161718, and several detection experiments have confirmed that polycrystalline TI films provide an attractive material platform for exploring the nature and practical application of TIs19202122.…”

Heterostructured ferromagnet–topological insulator with dual-phase magnetic properties

“…The interior of a topological insulator (TI) resembles that of a conventional insulator; however, the surface state is conductive. [1][2][3][4][5][6][7][8][9][10][11][12][13] Conning electrons to the surface state induces novel behaviour. For example, the momentum and spin of electrons in TIs are constrained to be perpendicular, due to strong spin-orbit interaction.…”