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Synthesis and quantum transport properties of Bi₂Se₃ topological insulator nanostructures.

Yan Y, Liao ZM, Zhou YB, Wu HC, Bie YQ, Chen JJ, Meng J, Wu XS, Yu DP - Sci Rep (2013)

Bottom Line: Bi₂Se₃ nanocrystals with various morphologies, including nanotower, nanoplate, nanoflake, nanobeam and nanowire, have been synthesized.Careful analysis of the SdH oscillations suggests the existence of Berry's phase π, which confirms the quantum transport of the surface Dirac fermions in both Bi₂Se₃ nanoplates and nanobeams without intended doping.The observation of the singular quantum transport of the topological surface states implies that the high-quality Bi₂Se₃ nanostructures have superiorities for investigating the novel physical properties and developing the potential applications.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871, P.R. China.

ABSTRACT
Bi₂Se₃ nanocrystals with various morphologies, including nanotower, nanoplate, nanoflake, nanobeam and nanowire, have been synthesized. Well-distinguished Shubnikov-de Haas (SdH) oscillations were observed in Bi₂Se₃ nanoplates and nanobeams. Careful analysis of the SdH oscillations suggests the existence of Berry's phase π, which confirms the quantum transport of the surface Dirac fermions in both Bi₂Se₃ nanoplates and nanobeams without intended doping. The observation of the singular quantum transport of the topological surface states implies that the high-quality Bi₂Se₃ nanostructures have superiorities for investigating the novel physical properties and developing the potential applications.

No MeSH data available.


Quantum transport properties of Bi2Se3 nanoplate and nanobeam.(a-d) are related to the Bi2Se3 nanoplates: (a) the SEM image of an individual Bi2Se3 nanoplate with Hall bar electrodes, (b) the magnetoresistance measured at 1.5 K, (c) the SdH oscillations observed after subtracting the magnetoresistance background, (d) Landau index vs 1/B, the peaks and valleys of the resistance oscillations correspond to N + 1/2 and N and are denoted by the circle and square symbols, respectively; (e-h) are related to the Bi2Se3 nanobeams: (e) the SEM image of an individual Bi2Se3 nanobeam with multi-terminal electrodes, (f) the resistance as a function of magnetic field measured at 1.5 K, (g) the resistance oscillations after subtracting the positive magnetoresistance background, (h) Landau index vs 1/B, the peaks and valleys of the resistance oscillations correspond to N and N + 1/2 and are denoted by the circle and square symbols, respectively.
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f4: Quantum transport properties of Bi2Se3 nanoplate and nanobeam.(a-d) are related to the Bi2Se3 nanoplates: (a) the SEM image of an individual Bi2Se3 nanoplate with Hall bar electrodes, (b) the magnetoresistance measured at 1.5 K, (c) the SdH oscillations observed after subtracting the magnetoresistance background, (d) Landau index vs 1/B, the peaks and valleys of the resistance oscillations correspond to N + 1/2 and N and are denoted by the circle and square symbols, respectively; (e-h) are related to the Bi2Se3 nanobeams: (e) the SEM image of an individual Bi2Se3 nanobeam with multi-terminal electrodes, (f) the resistance as a function of magnetic field measured at 1.5 K, (g) the resistance oscillations after subtracting the positive magnetoresistance background, (h) Landau index vs 1/B, the peaks and valleys of the resistance oscillations correspond to N and N + 1/2 and are denoted by the circle and square symbols, respectively.

Mentions: Electrical transport properties of the synthesized Bi2Se3 nanostructures were also studied. The as-grown Bi2Se3 nanostructures were transferred onto an insulator substrate. Micro-Hall devices based on the nanoplates and four-probe devices based on the nanobeams were fabricated via the processes including electron beam lithography, metal deposition, and lift-off. Typical SEM images of the devices are shown in Figures 4(a, e). As shown in Figure S4, the SEM image of a nanobeam device viewed using a 52° tilted sample stage indicates the nanobeam with a rectangle cross-section and a flat top surface. The temperature dependences of resistance for Bi2Se3 nanobeam and nanoplate are shown in Figure S5. The resistances for both samples decrease with decreasing temperature from 300 K to 20 K, showing a metallic behavior. Below 20 K, the resistance tends to saturate, which may result from the surface conduction and the bulk residual conduction.


Synthesis and quantum transport properties of Bi₂Se₃ topological insulator nanostructures.

Yan Y, Liao ZM, Zhou YB, Wu HC, Bie YQ, Chen JJ, Meng J, Wu XS, Yu DP - Sci Rep (2013)

Quantum transport properties of Bi2Se3 nanoplate and nanobeam.(a-d) are related to the Bi2Se3 nanoplates: (a) the SEM image of an individual Bi2Se3 nanoplate with Hall bar electrodes, (b) the magnetoresistance measured at 1.5 K, (c) the SdH oscillations observed after subtracting the magnetoresistance background, (d) Landau index vs 1/B, the peaks and valleys of the resistance oscillations correspond to N + 1/2 and N and are denoted by the circle and square symbols, respectively; (e-h) are related to the Bi2Se3 nanobeams: (e) the SEM image of an individual Bi2Se3 nanobeam with multi-terminal electrodes, (f) the resistance as a function of magnetic field measured at 1.5 K, (g) the resistance oscillations after subtracting the positive magnetoresistance background, (h) Landau index vs 1/B, the peaks and valleys of the resistance oscillations correspond to N and N + 1/2 and are denoted by the circle and square symbols, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3569629&req=5

f4: Quantum transport properties of Bi2Se3 nanoplate and nanobeam.(a-d) are related to the Bi2Se3 nanoplates: (a) the SEM image of an individual Bi2Se3 nanoplate with Hall bar electrodes, (b) the magnetoresistance measured at 1.5 K, (c) the SdH oscillations observed after subtracting the magnetoresistance background, (d) Landau index vs 1/B, the peaks and valleys of the resistance oscillations correspond to N + 1/2 and N and are denoted by the circle and square symbols, respectively; (e-h) are related to the Bi2Se3 nanobeams: (e) the SEM image of an individual Bi2Se3 nanobeam with multi-terminal electrodes, (f) the resistance as a function of magnetic field measured at 1.5 K, (g) the resistance oscillations after subtracting the positive magnetoresistance background, (h) Landau index vs 1/B, the peaks and valleys of the resistance oscillations correspond to N and N + 1/2 and are denoted by the circle and square symbols, respectively.
Mentions: Electrical transport properties of the synthesized Bi2Se3 nanostructures were also studied. The as-grown Bi2Se3 nanostructures were transferred onto an insulator substrate. Micro-Hall devices based on the nanoplates and four-probe devices based on the nanobeams were fabricated via the processes including electron beam lithography, metal deposition, and lift-off. Typical SEM images of the devices are shown in Figures 4(a, e). As shown in Figure S4, the SEM image of a nanobeam device viewed using a 52° tilted sample stage indicates the nanobeam with a rectangle cross-section and a flat top surface. The temperature dependences of resistance for Bi2Se3 nanobeam and nanoplate are shown in Figure S5. The resistances for both samples decrease with decreasing temperature from 300 K to 20 K, showing a metallic behavior. Below 20 K, the resistance tends to saturate, which may result from the surface conduction and the bulk residual conduction.

Bottom Line: Bi₂Se₃ nanocrystals with various morphologies, including nanotower, nanoplate, nanoflake, nanobeam and nanowire, have been synthesized.Careful analysis of the SdH oscillations suggests the existence of Berry's phase π, which confirms the quantum transport of the surface Dirac fermions in both Bi₂Se₃ nanoplates and nanobeams without intended doping.The observation of the singular quantum transport of the topological surface states implies that the high-quality Bi₂Se₃ nanostructures have superiorities for investigating the novel physical properties and developing the potential applications.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871, P.R. China.

ABSTRACT
Bi₂Se₃ nanocrystals with various morphologies, including nanotower, nanoplate, nanoflake, nanobeam and nanowire, have been synthesized. Well-distinguished Shubnikov-de Haas (SdH) oscillations were observed in Bi₂Se₃ nanoplates and nanobeams. Careful analysis of the SdH oscillations suggests the existence of Berry's phase π, which confirms the quantum transport of the surface Dirac fermions in both Bi₂Se₃ nanoplates and nanobeams without intended doping. The observation of the singular quantum transport of the topological surface states implies that the high-quality Bi₂Se₃ nanostructures have superiorities for investigating the novel physical properties and developing the potential applications.

No MeSH data available.