On locality effects

Yakir Aharonov, Benni Reznik

In certain topological effects the accumulation of a quantum phase shift is accompanied by a local observable effect. We show that such effects manifest a complementarity between nonlocal and local attributes of the topology, which is reminiscent but different from the usual wave-particle complementarity. This complementarity is not a consequence of noncommutativity, rather it is due to the noncanonical nature of the observables. We suggest that a local/nonlocal complementarity is a general feature of topological effects that are "dual" to the Aharonov-Bohm effect.

Travis Norsen

Michael E. Crenshaw, Charles M. Bowden

At densities that are typical of condensed matter, a propagating electromagnetic field mediates interactions between polarizable constituents of a material in what is known as the local-field effect. Previous investigations of the local-field effect have been limited to a single polarizable component of a nonlinear material. For multicomponent media, we have found that the interaction of laser radiation with an optically nonlinear component of condensed matter is fundamentally altered by the presence of another polarizable component as a result of the local-field effect. Novel effects include local-field enhancement effects, local cooperative decays, and coherence transfer and coherence exchange processes.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Vincent Vuatelet, Adam Rançon

Dynamical localization is the analog of Anderson localization in momentum space, where the system's energy saturates and the single-particle wave functions are exponentially localized in momentum space. In the presence of interactions, in the context of a periodically kicked Bose gas, it has been argued that dynamical localization persists. Focusing on the Tonks (strongly interacting) regime, we show that the many-body dynamically localized phase is effectively thermal, a clear deviation from the breaking of ergodicity observed in standard many-body localized systems. We relate the effective temperature to the driving parameters, and thus quantitatively describe the loss of coherence at large distances in this phase. Contrary to the noninteracting case, the momentum distribution decays as a power-law at large momenta, characterized by an effectively thermal Tan's contact. This is a rare example where driving and many-body (dynamical) localization lead to an effectively ergodic state.