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Fidelity freeze for a random matrix model with off-diagonal perturbation
1Fachbereich Physik der Philipps-Universität Marburg, Renthof 5, D-35032 Marburg, Germany. stoeckmann@physik.uni-marburg.de
Summary
Quantum system stability, measured by fidelity, is surprisingly robust against perturbations. This quantum fidelity freeze, even under strong perturbations, has implications for building stable quantum computers.
Area of Science:
- Quantum mechanics
- Quantum information theory
- Condensed matter physics
Background:
- Fidelity quantifies quantum system stability against perturbations.
- Linear-response theory showed fidelity decay freezes for specific perturbations (Prosen & Znidaric).
Purpose of the Study:
- Extend Prosen and Znidaric's findings to arbitrary perturbation strengths.
- Investigate fidelity freeze using supersymmetry calculations.
Main Methods:
- Supersymmetry calculations.
- Analysis of a quantum system with a Gaussian orthogonal ensemble Hamiltonian.
- Inclusion of a purely imaginary antisymmetric perturbation.
Main Results:
- The fidelity freeze is only slightly reduced compared to the linear-response approximation, even for strong perturbations.
- Exact calculations confirm the robustness of fidelity decay freeze.
Conclusions:
- Quantum system fidelity exhibits remarkable stability against perturbations.
- The findings suggest potential for designing more stable quantum computers.
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