  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 Su-Schrieffer-Heeger model, TPPs
are realized in a one-dimensional 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 near-field 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.
