IFEG   20353
INSTITUTO DE FISICA ENRIQUE GAVIOLA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
The Loschmidt Echo as a robust decoherence quantifier for many-body systems
Autor/es:
PABLO RENÉ ZANGARA; AXEL DAMIÁN DENTE; PATRICIA R. LEVSTEIN; HORACIO MIGUEL PASTAWSKI
Lugar:
Miami
Reunión:
Conferencia; Experimental Nuclear Magnetic Resonance Conference; 2012
Resumen:
High efficiency many-body dynamics of spin systems using the Graphical Processing Unit enables us to study decoherence in many-spin systems. We numerically evaluate the Loschmidt Echo, which in NMR is the signal recovered after the time-reversal of a many-spin evolution. In particular, we consider two spin chains with planar Hamiltonians, which are weakly coupled by a general spin-spin interaction, including Ising (ZZ) and planar (XY) terms. Only the Hamiltonian in one of the chains is inverted, and thus the Loschmidt Echo smoothly degrades. Several regimes are identified, and particularly we analyze the exponential one described by the Fermi Golden Rule. Accordingly, decoherence rates are obtained and analyzed separately for each physical process present in the inter-chain interaction.