Spin-spin indirect interaction at low energy excitation in zero-dimensional cavities

J A ANDRADE; ALIGIA A. A.; G. F. QUINTEIRO

JOURNAL OF PHYSICS CONDENSED MATTER

IOP PUBLISHING LTD

Año: 2011 vol. 23 p. 215304 - 215311

0953-8984

We solve the low-energy part of the spectrum of a model that describes a circularly polarizedcavity mode strongly coupled to two exciton modes, each of which is coupled to a localizedspin of arbitrary magnitude. In the regime in which the excitons and the cavity modes arestrongly coupled, forming polaritons, the low-energy part of the spectrum can be described byan effective spin model, which contains a magnetic field, an axial anisotropy, and an Isinginteraction between the localized spins. For detunings such that the low-energy states aredominated by nearly degenerate excitonic modes, the description of the low-energy states by asimple 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 asystem of transition-metal impurities embedded in quantum dots inside a micropillar.