Electrodynamic interaction between two atoms in near-field contact.

Area of Science:

• Quantum Electrodynamics
• Atomic Physics
• Theoretical Chemistry

Background:

• Near-field interactions between atoms are fundamental to quantum electrodynamics.
• Understanding these interactions requires advanced theoretical frameworks.
• Previous models often simplify atomic structures or electromagnetic field descriptions.

Purpose of the Study:

• To theoretically investigate quantum electrodynamic interactions between two single-electron atoms in near-field contact.
• To develop a propagator formalism for describing near-field space-time interactions.
• To analyze energy level renormalization in such systems.

Main Methods:

• Utilized an electromagnetic propagator formalism.
• Set up the atom-field Hamiltonian in the G-gauge, starting from the Coulomb Hamiltonian.
• Calculated intraparticle and interparticle energy renormalization for two-level and three-level atoms.

Main Results:

• Developed a propagator description for the retarded transverse electromagnetic field.
• Demonstrated energy level renormalization due to the transverse self-field.
• Obtained finite energy renormalization by not treating atoms as point-like.

Conclusions:

• The G-gauge formalism provides a consistent framework for near-field quantum electrodynamics.
• Finite energy renormalization is a key feature of these interactions.
• The theory offers insights relevant to multipole theory in interatomic electrodynamics.