130 citations · 757 across the 22 of their papers we have counts for
5 papers · 1 filter
Gaussian to Exponential Crossover in the Attenuation of Polarization Echoes in NMR
Gonzalo Usaj, Horacio M. Pastawski, Patricia R. Levstein
An ingenious pulse sequence devised by S. Zhang, B. H. Meier, and R. R. Ernst (Phys. Rev. Lett. {\bf 69}, 2149 (1992)) reverses the time evolution (``spin diffusion'') of the local…
Dynamically Driven Irreversibility in Many Body Quantum Systems: An experimental approach
Gonzalo Usaj, Horacio M. Pastawski, Patricia R. Levstein
The NMR technique allows one to create a non-equilibrium local polarization and to detect its later evolution. By a change of the sign of the effective dipolar Hamiltonian, the app…
Attenuation of polarization echoes in NMR: A study of the emergence of dynamical irreversibility in many-body quantum systems
Patricia R. Levstein, Gonzalo Usaj, Horacio M. Pastawski
The reversal of the time evolution of the local polarization in an interacting spin system involves a sign change of the effective dipolar Hamiltonian which refocuses the 'spin dif…
Quantum Interference Phenomena in the Local Polarization Dynamics of Mesoscopic Systems: An NMR Observation
Horacio M. Pastawski, Gonzalo Usaj, Patricia R. Levstein
It was predicted that local spin polarization in a ring of five dipolar coupled spins should present a particular fingerprint of quantum interferences reflecting both the discrete…
Quantum Dynamical Echoes in the Spin 'Diffusion' in Mesoscopic Systems
Horacio M. Pastawski, Patricia R. Levstein, Gonzalo Usaj
The evolution of local spin polarization in finite systems involves interference phenomena that give rise to {\bf quantum dynamical echoes }and non-ergodic behavior. We predict the…