We exhibit a specific implementation of the creation of geometrical phase through the state-space evolution generated by the dynamic quantum Zeno effect. That is, a system is guided through a closed loop in Hilbert space by means a sequence of closely spaced projections leading to a phase difference
Berry phases, quantum phase transitions and Chern numbers
β Scribed by H.A. Contreras; A.F. Reyes-Lega
- Publisher
- Elsevier Science
- Year
- 2008
- Tongue
- English
- Weight
- 114 KB
- Volume
- 403
- Category
- Article
- ISSN
- 0921-4526
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β¦ Synopsis
We study the relation between Chern numbers and quantum phase transitions (QPT) in the XY spin-chain model. By coupling the spin chain to a single spin, it is possible to study topological invariants associated to the coupling Hamiltonian. These invariants contain global information, in addition to the usual one (obtained by integrating the Berry connection around a closed loop). We compute these invariants (Chern numbers) and discuss their relation to QPT. In particular we show that Chern numbers can be used to label regions corresponding to different phases.
π SIMILAR VOLUMES
The Aharonov-Anandan geometric phase is generalized to non-unitary evolution, and is shown to be always real. By using a counter-example, which is exactly solvable, it is shown that Berry's geometric phase is not always the adiabatic limit of Aharonov-Anandan's geometric phase for a non-Hermitian dr