Radiative Corrections to the Polarizability of Helium

Abstract

The complete alpha(3) QED correction to the helium atom polarizability is computed assuming an infinite nuclear mass and found to be equal to 0.000030666(3) a.u., with the contribution from the electric-field dependence of the Bethe logarithm amounting to 0.000000193(2) a.u. After including the alpha(2) and alpha(3) corrections for the nuclear recoil and the leading part of the alpha(4) QED correction, we find that the molar polarizability of 4He is 0.51725419(9)(4) cm(3)/mol. The first of the two error bounds is dominated by the uncertainty of alpha(4) and higher-order QED corrections and the second reflects the uncertainty of the Avogadro constant.

Dynamic dipole polarizabilities of the Li atom and the Be+ion

“…The comparisons that have been done with fully relativistic calculations suggest that the estimates of the relativistic corrections are indeed accurate at this level. However, a more rigorous estimate using the Briet-Pauli Hamiltonian and perturbation theory would be desirable [40][41][42].…”

Noble Gas, Alkali and Alkaline Atoms Interacting With a Gold Surface

“…For the case of helium the respected polarizabilities have been computed variationally using basis sets of explicitly correlated functions. 9 For the other atoms considered we used dynamic polarizabilities published by Derevianko, Porsev and Babb. 10 We find it convenient to represent the potential by its short distance limit multiplied by a "damping function", accounting for the effects of retardation, which for the dipole case reads:…”

Progress towards the determination of thermodynamic temperature with ultra-low uncertainty

“…For low-temperature primary thermometry, this method was first proposed and pursued with an experimental design based on a cylindrical capacitor [21], which is not substantially different from its successive developments, as recently reviewed [22]. However, the recent progress in the ab initio calculation of the polarizability of helium [23] has substantially increased the ultimate accuracy which may potentially be achieved by DCGT. Triggered by this advance, considerable progress has been made in the following areas, all required to facilitate accurate thermodynamic temperature measurement by the method: (i) pressure balances as primary pressure standards [24]; (ii) the instrumentation used for capacitance measurements [25]; and (iii) the characterization of the elastic properties of the materials used for the construction of the capacitors.…”