Transport via double constrictions in integer and fractional topological insulators

Abstract

We study transport properties of the helical edge states of two-dimensional integer and fractional topological insulators via double constrictions. Such constrictions couple the upper and lower edges of the sample, and can be made and tuned by adding side gates to the system. Using renormalization group and duality mapping, we analyze phase diagrams and transport properties in each of these cases. Most interesting is the case of two constrictions tuned to resonance, where we obtain Kondo behavior, with a tunable Kondo temperature. Moving away from resonance gives the possibility of a metal-insulator transition at some finite detuning. For integer topological insulators, this physics is predicted to occur for realistic interaction strengths and gives a conductance $G$ with two temperature $T$ scales where the sign of $dG/dT$ changes; one being related to the Kondo temperature while the other is related to the detuning.

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Cited by in corpus (9)

• Fractional Charge and Spin States in Topological Insulator Constrictions
• Spin-thermoelectric transport induced by interactions and spin-flip processes in two dimensional topological insulators
• Polarized heat current generated by quantum pumping in two-dimensional topological insulators
• Interaction Protected Topological Insulators with Time Reversal Symmetry
• Topological Devil's staircase in atomic two-leg ladders
• Quantum criticality on a chiral ladder: an $SU(2)$ iDMRG study
• Current enhancement through a time dependent constriction in fractional topological insulators
• Tunneling into and between helical edge states - fermionic approach
• Tunneling between helical Majorana modes and helical Luttinger liquids