Breaking the Limitations of Temporal Modulation via Mixed Continuity Conditions

TL;DR

This paper introduces a unified framework that treats continuity conditions in time-varying media as design parameters, enabling novel wave phenomena like reflectionless amplification and reversible wave conversion.

Contribution

It develops a new approach to manipulate time-varying media by tuning continuity conditions, expanding possibilities for wave control and metamaterials design.

Findings

Enabled reflectionless wave amplification without bandgaps

Demonstrated reversible conversion between waves and static fields

Expanded the scope of time-varying metamaterials

Abstract

The conventional description of time-varying media assumes that electromagnetic fields evolve according to fixed continuity conditions during parameter jumps. Here we reveal that these conditions are not physical constraints but tunable design degrees of freedom. By developing a unified framework that treats continuity rules as engineerable parameters, we expand the scope of time-varying metamaterials and enable wave phenomena previously considered impossible. For instance, non-resonant, reflectionless wave amplification without momentum bandgaps, and reversible conversion between propagating waves and static fields for optical memory, etc. This work opens a new dimension for controlling light-matter interactions.