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Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses
Published on: June 7, 2018
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Many-body mobility edge in a mean-field quantum spin glass.
C R Laumann1, A Pal2, A Scardicchio3
1Department of Physics, University of Washington, Seattle, Washington 98195, USA and Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada.
Physical Review Letters
|November 29, 2014
Summary
The quantum random energy model reveals a many-body localization-delocalization transition in closed systems, occurring above the spin glass transition. This suggests dynamics freeze outside the typical glass phase.
Area of Science:
- Quantum physics
- Condensed matter physics
- Statistical mechanics
Background:
- The quantum random energy model (QREM) is a mean-field model for spin glass transitions.
- Understanding transitions in closed quantum systems is crucial for quantum dynamics.
Purpose of the Study:
- To investigate the presence and characteristics of a many-body localization-delocalization (MBLD) transition in the QREM when treated as a closed system.
- To compare the MBLD transition with the equilibrium spin glass transition.
Main Methods:
- Analytical treatment using the forward-scattering approximation.
- Application of replica techniques for theoretical analysis.
- Numerical simulations to validate theoretical predictions.
Main Results:
- The QREM exhibits an MBLD transition in a closed system, distinct from its equilibrium spin glass transition.
- The MBLD transition occurs at significantly higher energy densities than the spin glass transition.
- Numerical predictions align well with analytical results.
Conclusions:
- The closed system dynamics of the QREM freeze at energy densities beyond the conventional glass phase.
- The continuous change in eigenstate structure at the MBLD critical point suggests a family of critical theories may describe this transition.
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