Terahertz topological plasmon polaritons for robust temperature sensing
Abstract
We theoretically investigate the application of topological plasmon polaritons (TPPs) to temperature sensing for the first time. Based on an analogy of the topological edge states in the SuSchriefferHeeger model, TPPs are realized in a onedimensional intrinsic indium antimonide (InSb) microsphere chain. The existence of TPPs is demonstrated by analyzing the topology of the photonic band structures and the eigenmode distribution. By exploiting the temperature dependence of the permittivity of InSb in the terahertz range, the resonance frequency of the TPPs can be largely tuned by the temperature. Moreover, it is shown that the temperature sensitivity of the TPP resonance frequency can be as high as $0.0264~\mathrm{THz/K}$ at room temperature, leading to a figure of merit over 150. By calculating the LDOS near the chain, we further demonstrate that the temperature sensitivity of TPPs is experimentally detectable via nearfield probing techniques. This sensitivity is robust since TPPs are highly protected modes immune to disorder and can achieve a strong confinement of radiation. We envisage these TPPs can be utilized as promising candidates for robust and enhanced temperature sensing.
 Publication:

arXiv eprints
 Pub Date:
 November 2019
 arXiv:
 arXiv:1911.02760
 Bibcode:
 2019arXiv191102760W
 Keywords:

 Physics  Optics;
 Condensed Matter  Mesoscale and Nanoscale Physics
 EPrint:
 6 pages, 4 figures. comments are welcome