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Quantum Speed Limit for States with a Bounded Energy Spectrum
Gal Ness1, Andrea Alberti2,3,4, Yoav Sagi1
1Physics Department and Solid State Institute, Technion-Israel Institute of Technology, Haifa 32000, Israel.
Physical Review Letters
|October 14, 2022
Summary
Researchers discovered a new quantum speed limit for systems with bounded energy. This bound, dual to the Margolus-Levitin limit, is crucial for quantum information processing and defines new dynamical regimes.
Area of Science:
- Quantum physics
- Quantum information science
Background:
- Quantum speed limits dictate the maximum rate of quantum state evolution.
- Existing limits include the Mandelstam-Tamm bound (energy uncertainty) and Margolus-Levitin bound (mean energy relative to ground state).
Purpose of the Study:
- To identify and characterize an additional quantum speed limit for systems with bounded energy spectra.
- To explore the implications of this new bound for quantum information applications.
Main Methods:
- Theoretical analysis of quantum state evolution under a time-independent Hamiltonian.
- Investigation of systems with bounded energy spectra.
Main Results:
- A new quantum speed limit is identified, dependent on the difference between mean energy and the highest occupied eigenstate energy.
- This new bound is dual to the Margolus-Levitin bound.
- Three distinct dynamical regimes emerge, determined by the interplay of energy spread and mean, each governed by one of the three bounds.
Conclusions:
- The newly discovered bound is significant for quantum information processing, where bounded energy spectra are common.
- Understanding these dynamical regimes is essential for optimizing quantum computations and information storage.
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