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Exact Localized and Ballistic Eigenstates in Disordered Chaotic Spin Ladders and the Fermi-Hubbard Model
Thomas Iadecola1, Marko Žnidarič2,3
1Joint Quantum Institute and Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, Maryland 20742, USA.
Physical Review Letters
|August 7, 2019
Summary
We found unique quantum states in disordered systems, like the Fermi-Hubbard model. These states show surprising behaviors such as localization or ballistic transport, unlike typical states.
Area of Science:
- Quantum mechanics
- Condensed matter physics
- Disordered quantum systems
Background:
- Understanding many-body localization and transport in disordered quantum systems is crucial.
- Typical eigenstates in such systems are expected to exhibit diffusive transport.
- The Fermi-Hubbard model is a key model for studying interacting quantum systems.
Purpose of the Study:
- To demonstrate the existence of exact atypical many-body eigenstates in disordered, interacting one-dimensional quantum systems.
- To characterize the properties of these atypical eigenstates, including their transport behavior and entanglement.
- To compare the properties of atypical eigenstates with those of typical eigenstates.
Main Methods:
- Theoretical demonstration of exact atypical many-body eigenstates.
- Analysis of eigenstate properties such as energy density, number, and entanglement.
- Comparison of transport properties (localization vs. ballistic) of atypical and typical eigenstates.
- Discussion of experimental observation in cold-atom experiments.
Main Results:
- Existence of exact atypical many-body eigenstates in disordered interacting 1D quantum systems.
- These states, populated by noninteracting excitations, can exhibit Anderson localization or ballistic transport at any disorder strength.
- Atypical eigenstates display area-law entanglement.
- In contrast, typical eigenstates exhibit diffusive transport, consistent with chaotic quantum behavior.
Conclusions:
- Atypical eigenstates possess unique properties distinct from typical eigenstates in disordered quantum systems.
- These findings challenge conventional understanding of transport in such systems.
- The study proposes experimental verification in cold-atom setups, highlighting the robustness of these properties.
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