Generation and remote detection of THz sound using semiconductor superlattices

TL;DR

This paper presents a novel method for generating and detecting terahertz acoustic phonons using spatially separated semiconductor superlattices, revealing finite size effects and enabling high-frequency phonon studies.

Contribution

It introduces a new experimental setup for THz sound generation and detection with spatial separation, advancing phonon research in semiconductor superlattices.

Findings

Propagation of THz phonons confirmed between superlattices

Finite size effects observed and modeled

Frequency spectrum extends up to 1 THz

Abstract

The authors introduce a novel approach to study the propagation of high frequency acoustic phonons in which the generation and detection involves two spatially separated superlattices $\sim 1 {\rm \mu m}$ apart. Propagating modes of frequencies up to $\sim 1 {\rm THz}$ escape from the superlattice where they are generated and reach the second superlattice where they are detected. The measured frequency spectrum reveals finite size effects, which can be accounted for by a continuum elastic model.