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Finite-frequency optical absorption in 1D conductors and mott-hubbard insulators
1CNLS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 and Department of Physics, University of Evora, Apartado 94, P-7002-554 Evora, Portugal.
Physical Review Letters
|September 16, 2000
Summary
This study investigates frequency-dependent conductivity in the one-dimensional Hubbard model. Findings reveal a Drude peak and a critical exponent in the absorption spectrum, offering insights into metallic organic compounds.
Area of Science:
- Condensed matter physics
- Theoretical physics
Background:
- The one-dimensional Hubbard model is a fundamental system for studying strongly correlated electrons.
- Understanding optical properties of materials is crucial for technological applications.
Purpose of the Study:
- To investigate the frequency-dependent conductivity of the one-dimensional Hubbard model.
- To analyze the absorption spectrum and its components.
- To provide insights into the "far infrared puzzle" and optical properties of metallic organic chain compounds.
Main Methods:
- Utilizing a selection rule.
- Applying the Bethe ansatz.
- Leveraging symmetries associated with conservation laws.
Main Results:
- For metallic densities, the absorption spectrum exhibits two contributions: a Drude peak at zero frequency (omega = 0).
- A pseudogap separates the Drude peak from a broad absorption band.
- The lower edge of the absorption band is characterized by a nonclassical critical exponent.
Conclusions:
- The study clarifies the optical properties of the one-dimensional Hubbard model.
- The findings contribute to understanding the "far infrared puzzle" in metallic organic chain compounds.
- The identified critical exponent offers new perspectives on material behavior.
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