title: Spin-spin indirect interaction at low-energy excitation in zero-dimensional cavities.
abstract: We solve the low-energy part of the spectrum of a model that describes a circularly polarized cavity mode strongly coupled to two exciton modes, each of which is coupled to a localized spin of arbitrary magnitude. In the regime in which the excitons and the cavity modes are strongly coupled, forming polaritons, the low-energy part of the spectrum can be described by an effective spin model, which contains a magnetic field, an axial anisotropy, and an Ising interaction between the localized spins. For detunings such that the low-energy states are dominated by nearly degenerate excitonic modes, the description of the low-energy states by a simple effective Hamiltonian ceases to be valid and the effective interaction tends to vanish. Finally, we discuss a possible application to two-qubit quantum computing operations in a system of transition-metal impurities embedded in quantum dots inside a micropillar.
authors.affiliation: Centro Atómico Bariloche and Instituto Balseiro, Comisión Nacional de Energía Atómica, Bariloche, Argentina.
authors.forename: J A
authors.initials: JA
authors.lastname: Andrade
authors.forename: A A
authors.initials: AA
authors.lastname: Aligia
authors.forename: G F
authors.initials: GF
authors.lastname: Quinteiro