Topological semimetal coupled to nano-mechanical resonator

The detection of gapless Dirac point in semimetals is an important issue for the characterization of topological phase. While the direct measurements of spectral functions and magneto-conductance are widely employed, the strength of electronic signal is vanishingly small near Dirac point due to its low density of states. Here, we propose a way to detect the presence of Dirac node through the coupling to a nano mechanical resonator. Playing as a nonlinear circuit element, the quantum capacitance of topological semimetal induces an abnormal frequency shifting in the resonator near Dirac node. This quantum and mechanical setup will be ideal for the characterization of various topological matter and its boundary states.