Spin Subdiffusion in the Disordered Hubbard Chain
Maciej Kozarzewski1, Peter Prelovšek2,3, Marcin Mierzejewski4
1Institute of Physics, University of Silesia, 40-007 Katowice, Poland.
Physical Review Letters
|June 30, 2018
Summary
We found that in disordered one-dimensional systems, localized charges allow delocalized spins to move diffusively. This spin transport is governed by random interactions, with key factors being electron density and localization length.
Area of Science:
- Condensed Matter Physics
- Quantum Mechanics
- Disordered Systems
Background:
- The behavior of electrons and spins in disordered materials is complex.
- Understanding spin dynamics is crucial for quantum technologies.
Purpose of the Study:
- To develop an effective spin model for anomalous spin dynamics.
- To explain subdiffusive spin transport in the 1D Hubbard model with disorder.
Main Methods:
- Derivation of an effective spin model.
- Analysis of charge localization and spin delocalization.
- Investigating the role of random spin exchange interactions.
Main Results:
- Spins are delocalized despite charge localization.
- Subdiffusive spin transport arises from singular random spin exchange interactions.
- The subdiffusion exponent depends on Anderson localization length and electron density.
Conclusions:
- The derived spin model effectively explains anomalous spin dynamics.
- The findings hold for low particle densities and show qualitative agreement up to half filling.
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