title: Revised fine splitting of excitons in diamond
abstract: We study low-strain synthetic high pressure, high temperature diamonds by cathodoluminescence and observe novel fine structure in the free exciton and the boron-bound exciton emission. The basic spectral structure is a doublet with DeltaE approximately 11 meV common to both exciton spectra. This resolves the previously found inequivalence of free exciton ( approximately 7 meV) and bound exciton ( approximately 12 meV) fine splitting. It is argued that for a spin-orbit interaction Delta(0) much smaller than the excitonic binding ( E(X) approximately 80 meV) and the excitonic localization ( E(loc) approximately 51 meV) at the boron acceptor, the orbital momentum and the spin of the particles constituting the electron-hole pair are recoupled to form spin singlet and triplet exciton states as the elementary excitations.
authors.affiliation: Abteilung Halbleiterphysik, Universitat Ulm, 89069 Ulm, Germany.
authors.initials: R
authors.lastname: Sauer
authors.initials: H
authors.lastname: Sternschulte
authors.initials: S
authors.lastname: Wahl
authors.initials: K
authors.lastname: Thonke
authors.initials: TR
authors.lastname: Anthony