Related Experiment Videos
Berry phase for a spin 1/2 particle in a classical fluctuating field
Gabriele De Chiara1, G Massimo Palma
1NEST-INFM & Scuola Normale Superiore, piazza dei Cavalieri 7, I-56126 Pisa, Italy.
Physical Review Letters
|October 4, 2003
Summary
Fluctuations in control parameters affect the Berry phase for a spin 1/2 system. In the adiabatic limit, dynamical phase fluctuations cause dephasing, impacting quantum system behavior.
Area of Science:
- Quantum mechanics
- Condensed matter physics
- Quantum information
Background:
- The Berry phase describes the geometric phase acquired by a quantum system undergoing cyclic evolution.
- Understanding the stability of quantum states against environmental perturbations is crucial for quantum technologies.
Purpose of the Study:
- To analyze the impact of classical control parameter fluctuations on the Berry phase of a spin 1/2 system.
- To investigate the origin of dephasing in the adiabatic limit for such systems.
Main Methods:
- Theoretical analysis of a spin 1/2 system interacting with a time-varying magnetic field.
- Focus on adiabatic cyclic evolution and the role of parameter fluctuations.
Main Results:
- Explicit demonstration that fluctuations in classical control parameters influence the Berry phase.
- Identification of dynamical phase fluctuations as the cause of dephasing in the adiabatic regime.
Conclusions:
- Control parameter fluctuations are a key factor affecting the Berry phase in quantum systems.
- Dephasing in adiabatic quantum systems is directly linked to fluctuations in the dynamical phase.