Open Access. Powered by Scholars. Published by Universities.^{®}

#
Physical Sciences and Mathematics *Commons*^{™}

Open Access. Powered by Scholars. Published by Universities.^{®}

Articles **1** - **2** of ** 2**

## Full-Text Articles in Physical Sciences and Mathematics

Long-Range Interactions Of Hydrogen Atoms In Excited States. Iii. Ns−1s Interactions For N ≥ 3, Chandra M. Adhikari, V. Debierre, Ulrich D. Jentschura

#### Long-Range Interactions Of Hydrogen Atoms In Excited States. Iii. Ns−1s Interactions For N ≥ 3, Chandra M. Adhikari, V. Debierre, Ulrich D. Jentschura

*Physics Faculty Research & Creative Works*

The long-range interaction of excited neutral atoms has a number of interesting and surprising properties such as the prevalence of long-range oscillatory tails and the emergence of numerically large van der Waals C_{6} coefficients. Furthermore, the energetically quasidegenerate nP states require special attention and lead to mathematical subtleties. Here we analyze the interaction of excited hydrogen atoms in nS states (3 ≤ n ≤ 12) with ground-state hydrogen atoms and find that the C6 coefficients roughly grow with the fourth power of the principal quantum number and can reach values in excess of 240000 (in atomic units) for states with n ...

Long-Range Tails In Van Der Waals Interactions Of Excited-State And Ground-State Atoms, Ulrich D. Jentschura, V. Debierre

#### Long-Range Tails In Van Der Waals Interactions Of Excited-State And Ground-State Atoms, Ulrich D. Jentschura, V. Debierre

*Physics Faculty Research & Creative Works*

A quantum electrodynamic calculation of the interaction of an excited-state atom with a ground-state atom is performed. For an excited reference state and a lower-lying virtual state, the contribution to the interaction energy naturally splits into a pole term and a Wick-rotated term. The pole term is shown to dominate in the long-range limit, altering the functional form of the interaction from the retarded 1/R^{7} Casimir-Polder form to a long-range tail - provided by the Wick-rotated term - proportional to cos[2(E_{m} - E_{n})R/(ħc)]/R^{2}, where E_{m} < E_{n} is the energy of a virtual ...