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Threshold singularities in the dynamic response of gapless integrable models.
Vadim V Cheianov1, Michael Pustilnik
1Physics Department, Lancaster University, Lancaster LA1 4YB, United Kingdom.
Physical Review Letters
|June 4, 2008
Summary
We present a new method for analyzing dynamic response functions in integrable models. This approach accurately treats threshold singularities by using a deformed Hamiltonian and conventional field theory techniques.
Area of Science:
- Condensed Matter Physics
- Quantum Field Theory
Background:
- Integrable models exhibit complex dynamic response functions.
- Threshold singularities in these functions are challenging to treat exactly.
Purpose of the Study:
- To develop an asymptotically exact method for analyzing threshold singularities.
- To apply this method to spinless fermions with nearest-neighbor repulsion.
Main Methods:
- Recasting the problem using integrability to a deformed Hamiltonian.
- Employing conventional field theory methods on the local deformed Hamiltonian.
Main Results:
- An asymptotically exact treatment of threshold singularities is achieved.
- The exponent characterizing the singularity in the dynamic structure factor for spinless fermions was evaluated.
Conclusions:
- The developed method provides a powerful tool for studying dynamic properties of integrable systems.
- This technique simplifies the analysis of complex phenomena in condensed matter physics.
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