NMR Probe of Metallic States in Nanoscale Topological Insulators

Abstract

A 125Te NMR study of bismuth telluride nanoparticles as function of particle size revealed that the spin-lattice relaxation is enhanced below 33 nm, accompanied by a transition of NMR spectra from single to bimodal regime. The satellite peak features a negative Knight shift and higher relaxivity, consistent with core polarization from p-band carriers. Whereas nanocrystals follow a Korringa law in the range 140-420K, micrometer particles do so only below 200K. The results reveal increased metallicity of these nanoscale topological insulators in the limit of higher surface-to-volume ratios.

17 pages, 4 figures, 1 table

References in corpus (5)

• Few-layer Nanoplates of Bi2Se3 and Bi2Te3 with Highly Tunable Chemical Potential
• Helical Metal Inside a Topological Band Insulator
• Theoretical prediction of topological insulator in ternary rare earth chalcogenides
• Spin-lattice relaxation in bismuth chalcogenides
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Cited by in corpus (8)

• Understanding Bulk Defects in Topological Insulators from Nuclear-Spin Interactions
• A combined NMR and DFT study of Narrow Gap Semiconductors: The case of PbTe
• Nanoscale $\beta$-Nuclear Magnetic Resonance Depth Imaging of Topological Insulators
• Surface states and local spin susceptibility in doped three-dimensional topological insulators with odd-parity superconducting pairing symmetry
• Site-Specific Contributions to the Band Inversion in a Topological Crystalline Insulator
• Anomalous nuclear magnetic resonance spectra in Bi${}_2$Se${}_3$ nanowires
• NMR in an electric field: A bulk probe of the hidden spin and orbital polarizations
• Splitting of the topologically-protected Dirac cone without breaking time reversal symmetry