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arXiv · 1201.5610

Quantum criticality in Kondo quantum dot coupled to helical edge states of interacting 2D topological insulators

Chung-Hou Chung·Salman Silotri
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Abstract

We investigate theoretically the quantum phase transition (QPT) between the one-channel Kondo (1CK) and two-channel Kondo (2CK) fixed points in a quantum dot coupled to helical edge states of interacting 2D topological insulators (2DTI) with Luttinger parameter $0 1 that the 2CK fixed point can be unstable towards the 1CK fixed point and the system may undergo a quantum phase transition between 1CK and 2CK fixed points. The QPT in our model comes as a result of the combined Kondo and the helical Luttinger physics in 2DTI, and it serves as the first example of the 1CK-2CK QPT that is accessible by the controlled RG approach. We extract quantum critical and crossover behaviors from various thermodynamical quantities near the transition. Our results are robust against particle-hole asymmetry for 1/2<K<1.

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Chung-Hou Chung, Salman Silotri. 2012-01-26. Quantum criticality in Kondo quantum dot coupled to helical edge states of interacting 2D topological insulators. https://doi.org/10.1088/1367-2630/17/1/013005

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