Prediction of quantum many-body chaos in the protactinium atom

Abstract

Energy level spectrum of protactinium atom (Pa, Z = 91) is simulated with a CI calculation. Levels belonging to the separate manifolds of a given total angular momentum and parity J π exhibit distinct properties of many-body quantum chaos. Moreover, an extremely strong enhancement of small perturbations takes place. As an example, effective three-electron interaction is investigated and found to play a significant role in the system. Chaotic properties of the eigenstates allow one to develop a statistical theory and predict probabilities of different processes in chaotic systems.

High magnetic fields for fundamental physics

“…Sufficiently complex elements have spectra with chaotic properties [120][121][122]. The analysis techniques necessary for understanding these spectra bridge many disciplines, ranging from collisions in ultracold atoms [123] to dielectronic recombination (a process where an electron is captured by an atom and this capture is accompanied by excitation of a initially bound electron) [124] and the spectra of nuclei.…”

Coordination and thermodynamic properties of aqueous protactinium(v) by first-principle calculations

“…For instance, the five valence electrons of its free atom may spread in numerous ways on the valence 5f, 6d, 7s and 7p shells, which generates a quantum chaos of states even well before ionization. [2][3][4] In solution, protactinium chemistry is expected to be dominated by its +V oxidation state (formally free of valence electron), with potential occurrence under specific reducing conditions of the unstable +IV one (displaying one unpaired 5f electron in the ground state). 5 Therefore, the aqueous chemistry of protactinium could well have been dominated by easily identifiable and computable species.…”

Recent progress in laser spectroscopy of the actinides

“…Based on theoretical predictions indicating a potentially chaotic behavior of the atomic structure [243] these experimental levels were then investigated. Using statistical methods and simulation studies indicated that from the neighbor spacing and the level density for this atom the level distribution does no longer match classically integrable systems but rather shows an intrinsically fully chaotic behavior already at energies well below the first ionization potential.…”