# Density waves at the interface of a binary complex plasma

## TL;DR

This study investigates density wave phenomena at the interface of a phase-separated binary complex plasma under microgravity, revealing different excitation mechanisms and wave interactions that enhance understanding of plasma interface dynamics.

## Contribution

It provides the first detailed analysis of wave interactions at the interface of binary complex plasmas, highlighting distinct excitation mechanisms for different particle sizes.

## Key findings

- Big particles exhibit waves excited by two-stream instability.
- Small particles show heartbeat instability with reversed pulses.
- Identification of collision and merger zones at the interface.

## Abstract

Density waves were studied in a phase-separated binary complex plasma under microgravity conditions. For the big particles, waves were self-excited by the two-stream instability, while for small particles, they were excited by heartbeat instability with the presence of reversed propagating pulses of a different frequency. By studying the dynamics of wave crests at the interface, we recognize a "collision zone" and a "merger zone" before and after the interface, respectively. The results provide a generic picture of wave-wave interaction at the interface between two "mediums".