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arXiv · 1210.7241

2D compressibility of surface states on 3D topological insulators

D. S. L. Abergel·S. Das Sarma
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Abstract

We develop a theory for the compressibility of the surface states of 3D topological insulators and propose that surface probes of the compressibility via scanning single electron transistor microscopy will be a straightforward way to access the topological states without interference from the bulk states. We describe the single-particle nature of the surface states taking into account an accurate Hamiltonian for the bands and then include the contribution from electron--electron interactions and discuss the implications of the ultra-violet cutoff, including the universality of the exchange contribution when expressed in dimensionless units. We also compare the theory with experimentally obtained dμ/dn as extracted from angle-resolved photoemission spectroscopy measurements. Finally, we point out that interaction-driven renormalization of the Fermi velocity may be discernible via this technique.

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D. S. L. Abergel, S. Das Sarma. 2013-02-04. 2D compressibility of surface states on 3D topological insulators. https://doi.org/10.1103/physrevb.87.041407

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