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arXiv · 1007.1971

Gauge-field fluctuations in 3D topological Mott insulators

William Witczak-Krempa·Ting Pong Choy·Yong Baek Kim
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Abstract

We study the low-energy properties of three-dimensional (3D) topological Mott insulators which can be viewed as strong topological insulators of spinons interacting with a three-dimensional gauge field. The low-energy behavior of such systems is dominated by the two-dimensional (2D) gapless surface spinons coupled to the bulk gauge field. We find that a dimensional crossover from 3D to 2D in the gauge field fluctuations may occur as the systems thickness and/or temperature is varied. In the thin sample limit, the gauge field fluctuations effectively become 2D and the problem becomes analogous to the standard 2D spinon-gauge field theory. In the 3D limit, the bulk gauge field fluctuations lead to a low-energy theory for the coupled system that is more controlled than for the pure 2D case. We discuss various experimental signatures such as the heat capacity scaling as T ln 1/T as well as modified Ruderman-Kittel-Kasuya-Yoshida interactions on the surface.

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William Witczak-Krempa, Ting Pong Choy, Yong Baek Kim. 2011-01-06. Gauge-field fluctuations in 3D topological Mott insulators. https://doi.org/10.1103/physrevb.82.165122

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