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Published on: May 30, 2014
Semiclassical approach to survival probability at quantum phase transitions
Wen-ge Wang1, Pinquan Qin, Lewei He
1Department of Modern Physics, University of Science and Technology of China, Hefei, China. wgwang@ustc.edu.cn
Summary
We investigated survival probability decay at quantum phase transitions. Semiclassical theory predicts power-law decay for 1 degree of freedom and exponential decay for higher degrees of freedom.
Area of Science:
- Quantum mechanics
- Statistical physics
- Condensed matter physics
Background:
- Quantum phase transitions (QPTs) are critical points where quantum systems undergo drastic changes.
- Infinitely degenerate ground levels at QPTs present unique theoretical challenges.
- Survival probability decay is a key observable in understanding quantum dynamics near criticality.
Purpose of the Study:
- To investigate the decay of survival probability at quantum phase transitions.
- To analyze systems with infinitely degenerate ground levels at critical points.
- To compare semiclassical predictions with numerical simulations.
Main Methods:
- Semiclassical theory for survival probability decay.
- Numerical simulations in four distinct models.
- Analysis of decay behavior concerning the degrees of freedom (d).
Main Results:
- Semiclassical theory predicts power-law decay for d=1.
- Semiclassical theory predicts exponential decay for sufficiently large d.
- Numerical results in four models are used to verify these predictions.
Conclusions:
- The study confirms the distinct decay behaviors predicted by semiclassical theory.
- The degrees of freedom (d) play a crucial role in determining survival probability decay at QPTs.
- This work provides insights into quantum dynamics near critical points with degenerate ground states.
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