Continuous topological transition from metal to dielectric
Fan Yang1, Shaojie Ma2, Kun Ding3
1The Blackett Laboratory, Department of Physics, Imperial College London, London SW7 2AZ, United Kingdom; f.yang16@imperial.ac.uk j.pendry@imperial.ac.uk s.zhang@bham.ac.uk.
Summary
Metals and dielectrics are unified as topological states within metamaterials. A topological phase transition occurs at a metal filling ratio of one-half, redefining generalized metals and dielectrics.
Area of Science:
- Physics
- Materials Science
- Metamaterials
Background:
- Traditionally, metals and dielectrics exhibit contrasting electromagnetic properties, distinguished by the sign of their permittivity.
- Metals reflect electromagnetic waves, while dielectrics are transparent.
Purpose of the Study:
- To propose a unified topological understanding of metals and dielectrics.
- To investigate the continuous transition between metallic and dielectric states in metamaterials.
Main Methods:
- Modeling periodic metal-dielectric layered metamaterials.
- Analyzing the topological invariant during transitions.
- Investigating surface plasmon polaritons (SPPs) as topological edge states.
Main Results:
- Metals and dielectrics are presented as limiting cases of metamaterials.
- A topological phase transition occurs at a metal filling ratio of one-half.
- Metamaterials with filling ratios above or below one-half are termed "generalized metal" and "generalized dielectric," respectively.
Conclusions:
- The study unifies the understanding of metals and dielectrics through topology.
- Topological phase transitions are key to classifying metamaterial electromagnetic properties.
- Surface plasmon polaritons can be interpreted as topological edge states in this framework.
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