Relativistic graphene ratchet on semidisk Galton board

TL;DR

This study investigates a microwave-induced ratchet effect in graphene with a semidisk Galton board, revealing potential for room-temperature photodetectors due to graphene's high mean free path and unpolarized radiation response.

Contribution

It provides the first detailed numerical and analytical analysis of a graphene-based ratchet system, highlighting its advantages over traditional 2DEG in photogalvanic applications.

Findings

Ratchet currents are comparable in graphene and 2DEG at low temperatures.

Graphene's large mean free path enables strong ratchet transport at room temperature.

Graphene ratchets respond to unpolarized radiation, enhancing practical applicability.

Abstract

Using extensive Monte Carlo simulations we study numerically and analytically a photogalvanic effect, or ratchet, of directed electron transport induced by a microwave radiation on a semidisk Galton board of antidots in graphene. A comparison between usual two-dimensional electron gas (2DEG) and electrons in graphene shows that ratchet currents are comparable at very low temperatures. However, a large mean free path in graphene should allow to have a strong ratchet transport at room temperatures. Also in graphene the ratchet transport emerges even for unpolarized radiation. These properties open promising possibilities for room temperature graphene based sensitive photogalvanic detectors of microwave and terahertz radiation.