Flooding of wave functions in multi-dimensional mixed systems and the possibility of experimental observation.

Under suitable conditions quantum eigenfunctions for mixed systems localize neither on the regular nor on chaotic components in phase space. Such exotic quantum states are called amphibious states, and the flooding of wave functions from regular to chaotic regions, or in the opposite way, are predicted to occur when the eigenstates become amphibious. The emergence of such new states has so far been verified in rather artificial model systems. Here we explore how generically the flooding of wave functions takes place and whether it is an observable phenomenon even in laboratory experiments such as atomic matter-wave systems. Since the flooding occurs as a result of the strong correlation between different types of quantum localization, dynamical tunneling and dynamical localization, there are several competing factors, some of them accelerate but other do not. We study a quasi-periodic kicked rotor with generic phase space to search optimal situations to realize the flooding phenomenon and discuss the compatibility of competing factors between different types of quantum localization. [ABSTRACT FROM AUTHOR]