Séminaire de Physique ThéoriqueBlind spots between quantum states and the Loschmidt echo
Alfredo M. Ozorio de Almeida
Thursday 25 March 2010 14:00 - Tours - Salle 1180 (Bât E2)
The overlap between a quantum state and its image under tiny translations oscilates swiftly. Complete orthogonality occurs generically at isolated points: quantum blind spots. The cases of superpositions of coherent states and of Bohr-quantized states will be analyzed. Decoherence in the Markovian approximation lifts the overlap minima from zero. Generalizations of blind spots for continuous two-parameter groups of unitary transformations reveal novel aspects of the quantum Loschmidt echo.