Brownian motion of nonlinear oscillator in van der Waals trap

TL;DR

This study investigates how nonlinearity affects Brownian oscillators in van der Waals traps, revealing size, temperature, and structural influences on their dynamics and tunability for microscopic systems.

Contribution

It demonstrates the nonlinear effects on Brownian motion in van der Waals traps using simulations and approximations, highlighting tunable mechanical properties.

Findings

Smaller plates exhibit significant softening and temperature-induced softening.

Stiffness and friction coefficients are tunable via structural modifications.

Size and temperature effects are negligible for large-area plates.

Abstract

Van der Waals trap, a quantum fluctuation-induced potential characterized by short-range repulsive and long-range attractive forces, is intrinsically nonlinear. This work unveils the nonlinear effects on Brownian oscillators in the van der Waals trap using Langevin dynamics simulations and quasiharmonic approximations. While neither size- nor temperature-dependences of effective natural frequency is important for suspended plates of large areas, smaller ones with broader probability distributions are significantly softened and even a temperature-induced softening is observed. Despite the nonlinearity, the stiffness and the coefficient of friction are tunable by changing the thickness of coating and by modifying the size and the perforation condition of suspended plates, respectively, endowing the quantum trap with flexibilities of building up microscopic mechanical systems and probing near-boundary hydrodynamics.