Show by a theoretical and experimental argument that potassium atoms possess a permanent electric dipole moment based on the orbital angular momentum

TL;DR

This paper provides both theoretical and experimental evidence that potassium atoms have a permanent electric dipole moment linked to orbital angular momentum, challenging traditional symmetry assumptions.

Contribution

It demonstrates that the permanent EDM of potassium is due to orbital angular momentum, with no need for spin considerations, and links the EDM to the Runge-Lenz vector.

Findings

Measured potassium EDM as (1.58 ± 0.19 ± 0.13)×10⁻⁸ e·cm

Induced EDM is negligible (<1.5×10⁻¹⁶ e·cm)

EDM linked to orbital angular momentum and the Runge-Lenz vector

Abstract

The permanent electric dipole moment (EDM) of the ground state of potassium has been found by measuring the electric susceptibility. We find d(K)=(1.58 plus or minus 0.19(stat) plus or minus 0.13(syst)) times 10-8 e.cm and the induced EDM, d(ind) is less than1.5 times 10-16 e.cm, can be neglected. The experimental K material with purity 0.9995 is supplied by Strem Chemicals Co. USA. This paper shows that the permanent EDM is based on the orbital angular momentum (where the spin is irrelevant), and neither space inversion nor time reversal is a symmetry operation for an alkali atom. In fact, the famous Runge-Lenz vector M is simply the permanent EDM vector of an alkali atom. As early as 1926, W. Pauli calculated the energy levels of the hydrogen using the vector M. Therefore, our work may fall into the category of the most exciting discoveries during the past few decades.