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Description of van der Waals interactions using transformation optics.
Rongkuo Zhao1, Yu Luo, A I Fernández-Domínguez
1The Blackett Laboratory, Department of Physics, Imperial College London, London SW7 2AZ, United Kingdom. r.zhao@imperial.ac.uk
Physical Review Letters
|August 6, 2013
Summary
Calculating van der Waals forces between plasmonic nanoparticles is difficult. Transformation optics provides a new way to understand electromagnetic fields in tiny gaps, yielding universal formulas for these interactions.
Area of Science:
- Condensed matter physics
- Plasmonics
- Nanotechnology
Background:
- Calculating van der Waals interactions in closely spaced plasmonic nanoparticles is complex.
- Strong electromagnetic field concentration occurs in the nanometric gap, posing a challenge.
Purpose of the Study:
- To provide a theoretical framework for understanding van der Waals interactions between plasmonic nanoparticles.
- To develop universal analytical expressions for these interactions.
Main Methods:
- Utilizing the technique of transformation optics.
- Mapping small volumes to desired length scales to analyze electromagnetic fields.
- Deriving analytical expressions for van der Waals forces.
Main Results:
- Obtained universal analytical expressions for van der Waals interactions.
- Demonstrated the utility of transformation optics for analyzing nanoscale electromagnetic phenomena.
- Provided physical insight into electromagnetic field behavior in nanometric gaps.
Conclusions:
- Transformation optics offers a powerful tool for studying van der Waals forces in plasmonic systems.
- The derived expressions are applicable to spherical nanoparticles made of realistic metals at various separations.
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