FIB synthesis of Bi₂Se₃1D nanowires demonstrating the co-existence of Shubnikov–de Haas oscillations and linear magnetoresistance

Abstract

Since the discovery of topological insulators (TIs), there are considerable interests in demonstrating metallic surface states (SS), their shielded robust nature to the backscattering and study their properties at nanoscale dimensions by fabricating nanodevices. Here we address an important scientific issue related to TI whether one can clearly demonstrate the robustness of topological surface states (TSS) to the presence of disorder that does not break any fundamental symmetry. The simple straightforward method of FIB milling was used to synthesize nanowires of BiSe which we believe is an interesting route to test robustness of TSS and the obtained results are new compared to many of the earlier papers on quantum transport in TI demonstrating the robustness of metallic SS to gallium (Ga) doping. In the presence of perpendicular magnetic field, we have observed the co-existence of Shubnikov-de Haas oscillations and linear magnetoresistance (LMR), which was systematically investigated for different channel lengths, indicating the Dirac dispersive surface states. The transport properties and estimated physical parameters shown here demonstrate the robustness of SS to the fabrication tools triggering flexibility to explore new exotic quantum phenomena at nanodevice level.

Robust broad spectral photodetection (UV-NIR) and ultra high responsivity investigated in nanosheets and nanowires of Bi2Te3 under harsh nano-milling conditions

“…Note that the rise or decay time constant values are estimated here either using the exponential rise or decay fit equations. However we find that rise time or decay time constants in ms are in good agreement (Table 1 ) with the published literature and show competitiveness for photodetector applications and the fast response indicate the efficient carrier transport facilitated may be due to the robust nature of the TSS and high mobility 25 , 26 which is far better as compared with the transition metal dichalcogenides 27 , 28 . The broad spectral photodetection based on nanobelts, nanoribbons, nanosheets and emerging 2D materials have been recently published in a review article 29 .…”

“…Huang et al . observed that transport through TSS can tolerate the surface oxidation and molecules absorbed on the samples surface 40 and our previous work also showed the robustness of TSS towards the Ga ion milling and inherent material deformations 26 , 41 .…”

“…Note that topological insulators systems are predicated to be robust against any nonmagnetic impurities or deformations. Previously we have studied low temp transport studies and found quantum oscillations at low temp demonstrating the robust nature of TSS 26 , 41 . The absorption of light and generations of electron hole pairs are more effective in few layers of Bi 2 Te 3 .…”

3D Flake‐Like Bi2Te3 with Outstanding Lightweight Electromagnetic Wave Absorption Feature

“…Currently, Bi 2 Te 3 insulator material is generally produced by mechanical exfoliation and molecular beam epitaxy . Meanwhile, Bi 2 Te 3 thin films could be prepared by pulsed‐laser deposition, and Bi 2 Te 3 nanowires could be fabricated by the focused Ion beam method . However, those growth methods are not simple enough but difficult and great cost, thus it is difficult to industrialize in the microwave absorbing filed.…”

Investigation of photoconductive effect on Bi2Te3 epitaxial film

“…Recent measurements of photoconductive effects on Bi 2 Te 3 nanosheets and nanowires 12 and on Bi 2 Se 3 nanoflakes 14 and nanowires 15 were attributed to the conduction via topological surface states, mainly due to the large surface-to-volume ratio in these nanodevices. Also, Shubnikov-de Haas oscillations and Aharonov-Bohm interference effects measured on Bi 2 Se 3 nanowires fabricated by focused ion beam milling 33,34 were considered as a manifestation of robust topological surface states in nanostructures of this TI material. Moreover, the robustness of surface states against disorder was demonstrated by the measurement of magnetoconductance oscillations at low temperatures (1.8 K) on Bi 2 Te 3 nanotubes.…”