Magnetic Resonance of Excited States in Semiconductors and Related Nanostructures

Electron and nuclear spins in solids, coherently coupled to photons, provide promising resources for quantum information processing and sensing. Obtaining information about short-lived excited states is critical for realizing ultrafast all-optical spin control methods. After a brief review of early magnetic resonance studies of excited states, the following representative examples of the use of magnetic resonance spectroscopy to study excited states in wide-gap materials, semiconductors and nanostructures based on them will be considered: (1) optically detected magnetic resonance (ODMR), electron spin echo, electron-nuclear double resonance in the excited state on the example of self-trapped excitons in ionic-covalent silver halide crystals and nanocrystals, (2) ODMR and level anticrossing (LAC) spectroscopy of localized heavy-hole excitons in semiconductor quantum wells and superlattices, (3) LAC and ODMR in excited states of spin centers in diamond and silicon carbide, (4) the use of LAC and cross-relaxation for all-optical sensing with submicron spatial resolution.