Darmstadt 2008 – wissenschaftliches Programm

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A: Fachverband Atomphysik

A 21: Atomic systems in external fields

A 21.4: Vortrag

Donnerstag, 13. März 2008, 12:00–12:15, 3D

Quantum Monte Carlo studies of heavy atoms in neutron-star magnetic fields — •Dirk Meyer, Steffen Bücheler, Dirk Engel, Jörg Main, and Günter Wunner — 1. Institut für Theoretische Physik, Universität Stuttgart, 70550 Stuttgart

We have adapted the "released-phase" diffusion quantum Monte Carlo method to calculate the ground state energies of atoms and ions with nuclear charges from Z= 2, 3, 4, ⋯, 26 for magnetic field strengths relevant for neutron stars [1]. The novel feature of our study is the use of adiabatic approximation wave functions, augmented by a Jastrow factor, as guiding wave functions to initialize the quantum Monte Carlo prodecure. The calculations are motivated by the discovery of broad features in the thermal spectra of isolated neutron stars, which may be due to heavy atoms. Our results confirm previous results for nuclear charge numbers up to 10, and are the most accurate ones available in the literature to date for Z> 10. We also discuss the extension of the calculations to excited states and transition probabilities by using the correlation function Monte Carlo method [2].

[1] S. Bücheler, D. Engel, J. Main, and G. Wunner, Phys. Rev. A 76, 032501(2007)

[2] M. D. Jones, G. Ortiz, and D. Ceperley, Phys. Rev. E 55, 6202 (1997)