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Voltage-tunable nonequilibrium dispersion interactions
Christine M E Little1, Daniel S Kosov1
1College of Science and Engineering, James Cook University, Townsville, Queensland 4811, Australia.
The Journal of Chemical Physics
|July 20, 2026
Summary
We developed a theory for dispersion interactions in nanostructures driven by voltage. This work shows that applied voltage can significantly enhance attractive interactions or even lead to repulsive forces, a key finding for quantum systems.
Area of Science:
- Quantum mechanics
- Condensed matter physics
- Nanotechnology
Background:
- Dispersion interactions are crucial in nanostructures.
- Understanding these interactions out of equilibrium is challenging.
- Current theories often focus on thermal equilibrium conditions.
Purpose of the Study:
- To develop a theoretical framework for dispersion interactions in driven nanostructures.
- To analyze the effects of applied bias voltage on these interactions.
- To generalize equilibrium fluctuation-dissipation theorems to nonequilibrium conditions.
Main Methods:
- Development of a nonequilibrium Green's function theory.
- Derivation of interaction energy from two-particle Green's functions.
- Decomposition of interaction energy into charge noise and dissipation.
- Introduction of a generalized Kubo-Martin-Schwinger ratio.
Main Results:
- The theory provides a transparent decomposition of interaction energy.
- Applied voltage can enhance attractive dispersion interactions by an order of magnitude.
- Nonequilibrium conditions can lead to repulsive dispersion interactions, unlike in equilibrium.
- Population inversion can potentially reverse the sign of the interaction.
Conclusions:
- The developed theory offers a new perspective on dispersion forces in driven quantum systems.
- Nonequilibrium effects significantly alter dispersion interactions, enabling new control mechanisms.
- This work opens avenues for designing nanostructures with tunable interactions.
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