We discuss the behavior of a quantum 1/2 spin coupled to a time dependent magnetic field, which can be quasiperiodic or random. For a quasiperiodic field, the time evolution of the system on a coarse grained space has autocorrelation, which does not decay, and positive topological entropy. The information complexity diverges as a stretched exponential, although the Shannon entropy is zero and there is no divergence of nearby orbits. A simple random process is introduced in order to reproduce the main qualitative features of the observed weakly complex behavior.
Complexity in Quantum Systems / Crisanti, Andrea; Falcioni, Massimo; G., Paladin; M., Serva; Vulpiani, Angelo. - In: PHYSICAL REVIEW E. - ISSN 1063-651X. - STAMPA. - 50:(1994), pp. 138-144. [10.1103/PhysRevE.50.138]
Complexity in Quantum Systems
CRISANTI, Andrea;FALCIONI, Massimo;VULPIANI, Angelo
1994
Abstract
We discuss the behavior of a quantum 1/2 spin coupled to a time dependent magnetic field, which can be quasiperiodic or random. For a quasiperiodic field, the time evolution of the system on a coarse grained space has autocorrelation, which does not decay, and positive topological entropy. The information complexity diverges as a stretched exponential, although the Shannon entropy is zero and there is no divergence of nearby orbits. A simple random process is introduced in order to reproduce the main qualitative features of the observed weakly complex behavior.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
