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Two-exciton bound state quantum self-trapping in an extended star graph
1Institut UTINAM, Université de Franche-Comté, CNRS UMR 6213, 25030 Besançon Cedex, France.
The Journal of Chemical Physics
|April 23, 2022
Summary
Quantum self-trapping in star graphs is explored using the Bose-Hubbard model. Energy localization occurs for branch numbers N ≥ 3, intensifying with higher N, unlike linear chains (N=2).
Area of Science:
- Quantum physics
- Condensed matter physics
Background:
- The Bose-Hubbard model describes interacting bosons in a lattice.
- Quantum self-trapping is a phenomenon where energy localizes in a system.
Purpose of the Study:
- To investigate quantum self-trapping in an extended star graph using the Bose-Hubbard model.
- To analyze the influence of the number of branches (N) on energy localization.
Main Methods:
- Application of the attractive Bose-Hubbard model.
- Analysis in the strong coupling limit with two excitons on the core.
- Examination of system dynamics based on the branch number N.
Main Results:
- For N=2, the star graph behaves like a linear chain, preventing energy self-localization.
- For N ≥ 3, eigenstates restructure, leading to a low-energy state with localized pairs on the core.
- This localized state drives quantum self-trapping, which is amplified as N increases.
Conclusions:
- The branch number N critically determines energy localization in star graphs.
- Quantum self-trapping is achievable and controllable in these systems for N ≥ 3.
- The findings offer insights into energy dynamics in complex quantum networks.
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