Topological quantization of energy transport in micro- and nano-mechanical lattices

Chih-Chun Chien, Kirill A. Velizhanin, Yonatan Dubi, B. Robert Ilic, Michael Zwolak

Published 2017-07-20Version 1

Topological effects are emerging as one of the central paradigms of physics, from condensed matter to cold atoms to quantum computation. These effects are typically discussed in the context of quantum physics, with only a few focusing on the classical regime and fewer still connecting topology and energy transport. Here, we demonstrate the role of topology in determining energy transport through dimerized micro- and nano-mechanical lattices in the classical regime, i.e., essentially "masses and springs", a hallmark example of Newtonian physics with relevance to many nanoscale experimental systems. We show that the thermal conductance factorizes into topological and non-topological components. The former takes on three discrete values and arises due to the appearance of edge modes that prevent good contact between the heat reservoirs and the bulk phonons, giving a length-independent reduction of the conductance. In essence, energy input at the boundary mostly stays at the boundary, an effect robust against disorder and nonlinearity. These results bridge two seemingly disconnected disciplines of physics, namely topology and thermal transport, and suggest ways to engineer thermal contacts and control heat flow, opening a novel direction to explore the ramifications of topological properties on nanoscale technology.