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Transitional Goos-Hänchen effect due to the topological phase transitions
Optics Express
|September 7, 2018
Summary
The Goos-Hänchen effect in silicene shows sharp spatial and angular shifts during topological phase transitions. This transitional effect, linked to optical conductivity, offers a direct optical method for measuring topological properties.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Optics
Background:
- The Goos-Hänchen (GH) effect describes the spatial or angular shift of a reflected light beam.
- Silicene, a 2D material analogous to graphene, exhibits tunable topological phases.
- Topological phase transitions in materials can be induced by external stimuli like electric fields or light.
Purpose of the Study:
- To investigate the Goos-Hänchen effect in silicene under conditions of topological phase transitions.
- To explore the relationship between topological phase transitions and observable changes in the GH effect.
- To assess the potential of using the GH effect as an optical probe for topological properties.
Main Methods:
- Theoretical analysis of a Gaussian beam interacting with silicene.
- Modulation of silicene's topological phase using external electric fields and circularly polarized light.
- Calculation of spatial and angular shifts in the Goos-Hänchen effect.
Main Results:
- A sharp jump in both spatial and angular shifts of the Goos-Hänchen effect was observed during silicene's topological phase transitions.
- The transitional GH effect is directly linked to the transitional optical conductivity, which is governed by Berry curvature and Chern numbers.
- The observed phenomena are applicable to other 2D atomic crystals within the graphene family.
Conclusions:
- Topological phase transitions in silicene significantly alter the Goos-Hänchen effect, causing distinct shifts.
- The transitional Goos-Hänchen effect provides a direct optical measurement method for determining Berry curvature, Chern numbers, and topological phase transitions.
- This research opens avenues for optical characterization of topological properties in 2D materials.
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