Superluminal Tachyonlike Excitations of Dirac Fermions in a Topological Insulator Junction

Abstract

We have considered a system of two topological insulators and have determined the properties of the surface states at the junction. Here we report that these states, under certain conditions exhibit superluminous (tachyonic) dispersion of the Dirac fermions. Although superluminal excitations are known to exist in optical systems, this is the first demonstration of possible tachyonic excitations in a purely electronic system. The first ever signature of tachyons could therefore be found experimentally in a topological insulator junction.

5 pages, 4 figures

References in corpus (3)

• Topological Surface States Protected From Backscattering by Chiral Spin Texture
• Finite size effects of helical edge states in HgTe/CdTe quantum wells
• Junction between surfaces of two topological insulators

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• Nonlinear Dirac Cones
• Edge states of a three-dimensional topological insulator
• Transport across a junction of topological insulators and a superconductor
• Gapless interface states at the junction between two topological insulators
• Confining electrons on a topological insulator surface using potentials and a magnetic field
• Optical analogue of spontaneous symmetry breaking induced by tachyon condensation in amplifying plasmonic arrays
• Transport in a thin topological insulator with potential and magnetic barriers
• The Fractional Quantum Hall Effect of Tachyons in a Topological Insulator Junction
• Crystalline topological states at a topological insulator junction