A topological wave transistor protected by the Euler characteristic

作者：Sklan Sophia R; Li Baowen^*

来源：Journal of Applied Physics, 2018, 123(22): 224505.

DOI：10.1063/1.5025722

Although topological materials have recently seen tremendous development, their applications have remained elusive. Simultaneously, there exists considerable interest in pushing the limits of topological materials, including the exploration of new forms of topological protection and the establishment of topologically protected order in non-electronic systems. Here, we develop some novel forms of topological order (i.e., topological charges), primarily the Euler characteristic as well as manifold class. We further demonstrate that these topological orders can protect bulk current transmission, even when the topologically trivial phase possesses an arbitrarily large band gap. Such a transition between topologically trivial, periodic dispersion and topologically non-trivial, aperiodic dispersion can be obtained by spatio-temporal modulation, such as the anomalous Doppler shift of waves in a gapped periodic medium. Since a wave's momentum can induce an anomalous Doppler shift, we thus establish that such a transition can be used to construct a truly rigorous transistor (i.e., with switching and gain) for bosonic waves (light, sound, etc.) and that such a transistor should be experimentally realizable. Our work suggests that additional topological charges may become relevant in moving beyond topological electronics. Published by AIP Publishing.

• 出版日期2018-6-14