Floquet spin states in OLEDs

Electron and hole spins in organic light-emitting diodes constitute prototypical two-level systems for the exploration of the ultrastrong-drive regime of light-matter interactions. Floquet solutions to the time-dependent Hamiltonian of pairs of electron and hole spins reveal that, under non-perturbative resonant drive, when spin-Rabi frequencies become comparable to the Larmor frequencies, hybrid light-matter states emerge that enable dipole-forbidden multi-quantum transitions at integer and fractional g-factors. To probe these phenomena experimentally, we develop an electrically detected magnetic-resonance experiment supporting oscillating driving fields comparable in amplitude to the static field defining the Zeeman splitting; and an organic semiconductor characterized by minimal local hyperfine fields allowing the non-perturbative light-matter interactions to be resolved. The experimental confirmation of the predicted Floquet states under strong-drive conditions demonstrates the presence of hybrid light-matter spin excitations at room temperature. These dressed states are insensitive to power broadening, display Bloch-Siegert-like shifts, and are suggestive of long spin coherence times, implying potential applicability for quantum sensing. Organic semiconductors employed in light-emitting diodes (OLEDs) allow for magnetic resonance studies that explore light-matter interactions in the ultrastrong-drive regime, where the Rabi frequency exceeds the Larmor frequency. The authors report the formation of Floquet spin states in OLEDs.

Automated summary

The study explores spin excitations of electron and hole spins in organic light-emitting diodes, confirming the existence of hybrid light-matter states under ultrastrong-drive conditions. These dressed states are insensitive to power broadening, exhibit long spin coherence times, and have potential applications in quantum sensing.