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Doublon relaxation in the Bose-Hubbard model
A L Chudnovskiy1, D M Gangardt, A Kamenev
1I. Institut für Theoretische Physik, Universität Hamburg, Hamburg, Germany.
Physical Review Letters
|April 3, 2012
Summary
The decay of high-energy doublons (double occupancy states) in narrow-band lattices is slow due to many-particle excitations. Researchers found this decay exponent can be exactly calculated when average occupation is low, using a quasiclassical approach.
Area of Science:
- Condensed matter physics
- Quantum mechanics
- Many-body physics
Background:
- High-energy double occupancy states, or doublons, are crucial in understanding electron correlations in narrow-band systems.
- The decay of these states typically involves complex many-particle excitations, leading to long relaxation times.
Purpose of the Study:
- To investigate the decay dynamics of doublons in narrow-band lattices.
- To determine if the decay exponent can be analytically evaluated under specific conditions.
- To develop a theoretical framework for calculating decay amplitudes.
Main Methods:
- Development of a quasiclassical approach.
- Calculation of high-order tree-level decay amplitudes.
- Analysis of doublon decay under conditions of small average occupation number.
Main Results:
- The decay of doublons requires the creation of coherent many-particle excitations.
- This process results in exponentially long relaxation times for the doublon state.
- The decay exponent can be evaluated exactly when the average occupation number is sufficiently small.
Conclusions:
- The quasiclassical approach provides an exact method for evaluating the doublon decay exponent under low occupation conditions.
- Understanding doublon decay dynamics is essential for predicting the behavior of correlated electron systems.
- This work offers a new theoretical tool for studying relaxation processes in condensed matter systems.
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