01691nas a2200169 4500008004100000245007000041210006900111260001500180300001300195490000600208520118500214100002701399700001301426700001901439700002601458856003701484 2018 eng d00aFractal Universality in Near-Threshold Magnetic Lanthanide Dimers0 aFractal Universality in NearThreshold Magnetic Lanthanide Dimers c2018/02/16 aeaap83080 v43 a
Ergodic quantum systems are often quite alike, whereas nonergodic, fractal systems are unique and display characteristic properties. We explore one of these fractal systems, weakly bound dysprosium lanthanide molecules, in an external magnetic field. As recently shown, colliding ultracold magnetic dysprosium atoms display a soft chaotic behavior with a small degree of disorder. We broaden this classification by investigating the generalized inverse participation ratio and fractal dimensions for large sets of molecular wave functions. Our exact close-coupling simulations reveal a dynamic phase transition from partially localized states to totally delocalized states and universality in its distribution by increasing the magnetic field strength to only a hundred Gauss (or 10 mT). Finally, we prove the existence of nonergodic delocalized phase in the system and explain the violation of ergodicity by strong coupling between near-threshold molecular states and the nearby continuum.
1 aMakrides, Constantinos1 aLi, Ming1 aTiesinga, Eite1 aKotochigova, Svetlana uhttps://arxiv.org/abs/1802.09586