Microscopic Ampère current-current interaction

With the rapid development of modern measurement techniques, the energy resolution of 1 meV can now be easily obtained. Generally, the driving mechanisms of the physical, chemical or biological processes of the matters or the living organisms on Earth at about 1 meV energy scale are assumed to stem from the fundamental microscopic Coulomb interaction and its various reduced ones as well as the relativistic corrections. Examples are such as the electron-phonon interaction, the Heisenberg exchange spin interaction, the superexchange interaction, the van der Waals interaction, the spin-orbit interaction, the Breit interaction, etc. In this article, by using a path integral approach on a non-relativistic quantum electrodynamics theory, we show that there is another fundamental microscopic interaction at this energy scale, the microscopic Ampère current-current interaction. It has time-dependent dynamical feature and can be the driving interaction of the physical or chemical properties of the matters or the biological activity of the living organisms on Earth at about 1 meV energy scale. A new Ampère-type exchange spin interaction is also found with a magnitude about 10^-4 of the well-known Coulomb interaction relevant Heisenberg exchange spin interaction.