Single-particle model for a granular ratchet

TL;DR

This paper presents a simple single-particle model for a granular ratchet, analyzing how vibration strength, sawtooth roughness, and restitution coefficient influence horizontal transport and current direction.

Contribution

It introduces a minimal model for granular ratchet behavior and maps out the parameter regimes leading to different transport regimes.

Findings

Horizontal transport depends on vibration strength and sawtooth roughness.

Identifies parameter regions for no current, normal current, and current reversal.

Provides a phase diagram summarizing transport regimes.

Abstract

A simple model for a granular ratchet corresponding to a single grain bouncing off a vertically vibrating sawtooth-like base is studied. Depending on the vibration strength, the sawtooth roughness and the restitution coefficient, horizontal transport in both the preferred and unfavoured directions is observed. A phase diagram indicating the regions in parameter space where each of the three possible regimes (no current, normal current, and current reversal) occurs is presented.