Microscopic Ampère current-current interaction

With the rapid development of modern measurement techniques, the energy resolution of 1meV 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 1meV energy scale are assumed to stem from the fundamental microscopic Coulomb interaction, its various reduced ones and the relativistic corrections. In this article, by using a path integral approach on a non-relativistic quantum electrodynamics theory, we show that there is another fundamental microscopic electromagnetic 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, chemical or biological processes at about 1meV energy scale. A new Ampère-type exchange spin interaction is also found with a magnitude about 10−4 of the well-known Heisenberg exchange spin interaction. •A path integral approach on a non-relativistic quantum electrodynamics theory is developed.•The fundamental microscopic Ampère current-current interaction is revisited.•A new Ampère-type exchange spin interaction is found.