Before revision:  Moreover,  half-coated (Janus ) tracer performs a composite random walk combining power-law-tail distributed L\'{e}vy flights with Brownian jiggling at low coating concentration, but undergoes an enhanced directional transport  when coating concentration is high.
After revision:  Moreover, Janus ( half-coated (Janus ) tracer performs a composite random walk combining power-law-tail distributed L\'{e}vy flights with Brownian jiggling at low coating concentration, but undergoes an enhanced directional transport when coating concentration is high.