Fabrication and Characterization of Topological Insulator Bi${}_2$Se${}_3$ Nanocrystals

Abstract

In the recently discovered class of materials known as topological insulators, the presence of strong spin-orbit coupling causes certain topological invariants in the bulk to differ from their values in vacuum. The sudden change of invariants at the interface results in metallic, time reversal invariant surface states whose properties are useful for applications in spintronics and quantum computation. However, a key challenge is to fabricate these materials on the nanoscale appropriate for devices and probing the surface. To this end we have produced 2 nm thick nanocrystals of the topological insulator Bi${}_2$Se${}_3$ via mechanical exfoliation. For crystals thinner than 10 nm we observe the emergence of an additional mode in the Raman spectrum. The emergent mode intensity together with the other results presented here provide a recipe for production and thickness characterization of Bi${}_2$Se${}_3$ nanocrystals.

4 pages, 3 figures (accepted for publication in Applied Physics Letters)

References in corpus (4)

• Bulk Fermi surface coexistence with Dirac surface state in Bi${}_2$Se${}_3$: a comparison of photoemission and Shubnikov-de Haas measurements
• Interference effect on Raman spectrum of graphene on SiO_2/Si
• Fabrication and Characterization of Topological Insulator Bi${}_2$Se${}_3$ Nanocrystals
• Stability of exfoliated Bi${}_2$Sr${}_2$Dy${}_x$Ca${}_{1-x}$Cu${}_2$O${}_{8+\delta }$ studied by Raman microscopy

Cited by in corpus (14)

• Spin-orbit excitations and electronic structure of the putative Kitaev magnet $\alpha$-RuCl${}_3$
• Sn-doped Bi1.1Sb0.9Te2S, a bulk topological insulator with ideal properties
• Interaction of Phonons and Dirac Fermions on the Surface of Bi2Se3: A Strong Kohn Anomaly
• Possible Structural Transformation and Enhanced Magnetic Fluctuations in Exfoliated $\alpha$-RuCl${}_3$
• Nonstoichiometric doping and Bi antisite defect in single crystal Bi2Se3
• Fabrication and Characterization of Topological Insulator Bi${}_2$Se${}_3$ Nanocrystals
• Helical fluctuations in the Raman response of the topological insulator Bi2Se3
• Surface vibrational modes of the topological insulator Bi${}_2$Se${}_3$ observed by Raman spectroscopy
• Local phonon mode in thermoelectric Bi2Te2Se from charge neutral antisites
• Topological Insulator Thin Films Starting from the Amorphous Phase - Bi${}_2$Se${}_3$ as Example
• AFM and Raman studies of topological insulator materials subject to argon plasma etching
• Low vibration high numerical aperture automated variable temperature Raman microscope
• Absence of Magnetic Fluctuations in the Ferromagnetic/Topological Heterostructure EuS/Bi${}_2$Se${}_3$
• Interface electronic structure at the topological insulator - ferrimagnetic insulator junction