Purcell modification of Auger and interatomic Coulombic decay

An excited two-atom system can decay via different competing relaxation processes. If the excess energy is sufficiently high may not only relax spontaneous emission but also undergo interatomic Coulombic (ICD) or even Auger decay. We provide analytical expressions for rates by including them into same quantum optical framework on basis of macroscopic electrodynamics. By comparing in free space we derive atomic properties determining which channel dominates relaxation. show that modifying excitation propagation respective process bodies, spirit Purcell effect, one control ratio between two dominating rates. relate magnitude effect to characteristic length scales each process, analyse impact a simple close-by surface onto general detail and discuss cavity finally apply our theory example doubly HeNe-dimer.