Role of time scales for the non-Gaussianity of the Brownian motion combined with intermittent adsorption

• Displacements with intermittent adsorption can lead to Gaussian-like distribution.
• Relative time scales between the adsorption and the frame interval is important.
• The large deviation principle is employed to reveal the characteristics.

Single-molecule tracking data near solid surfaces contain information on diffusion that is potentially affected by adsorption. However, molecular adsorption can occur in an intermittent manner, and the overall phenomenon is regarded as slower yet normal diffusion if the time scale of each adsorption event is sufficiently shorter than the interval of data acquisition. We compare simple numerical model systems that vary in the time scale of adsorption event while sharing the same diffusion coefficient, and show that the shape of the displacement distribution depends on the time resolution. We also evaluate the characteristics by statistical quantities related to the large deviation principle. We show that the characteristic time scale of the intermittent phenomena is elucidated when the time resolution of the observation is sufficiently fine and the amount of data is sufficiently large to evaluate the intermittency.