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arXiv · 1308.5982

Structure factor of interacting one-dimensional helical systems

Suhas Gangadharaiah·Thomas L. Schmidt·Daniel Loss
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Abstract

We calculate the dynamical structure factor S(q, {\omega}) of a weakly interacting helical edge state in the presence of a magnetic field B. The latter opens a gap of width 2B in the single-particle spectrum, which becomes strongly nonlinear near the Dirac point. For chemical potentials |{\mu}| > B, the system then behaves as a nonlinear helical Luttinger liquid, and a mobile-impurity analysis reveals interaction-dependent power-law singularities in S(q,{\omega}). For |{\mu}| < B, the low-energy excitations are gapped, and we determine S(q,{\omega}) by using an analogy to exciton physics.

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Suhas Gangadharaiah, Thomas L. Schmidt, Daniel Loss. 2013-08-27. Structure factor of interacting one-dimensional helical systems. https://doi.org/10.1103/physrevb.89.035131

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