Chiappe, Guillermo, Fernández-Rossier, Joaquín, Louis, Enrique, Anda, Enrique V.
Anisotropic exchange interaction induced by a single photon in semiconductor microcavities
CHIAPPE, G., et al. “Anisotropic exchange interaction induced by a single photon in semiconductor microcavities”. Physical Review B. Vol. 72, No. 24 (2005). ISSN 1098-0121, pp. 245311-1/5
URI: http://hdl.handle.net/10045/25223
DOI: 10.1103/PhysRevB.72.245311
ISSN: 1098-0121 (Print)
Abstract: 
We investigate coupling of localized spins in a semiconductor quantum dot embedded in a microcavity. The lowest cavity mode and the quantum dot exciton are coupled and close in energy, forming a polariton. The fermions forming the exciton interact with localized spins via exchange. Exact diagonalization of a Hamiltonian in which photons, spins, and excitons are treated quantum mechanically shows that a single polariton induces a sizable indirect anisotropic exchange interaction between spins. At sufficiently low temperatures strong ferromagnetic correlations show up without an appreciable increase in exciton population. In the case of a (Cd,Mn)Te quantum dot, Mn-Mn ferromagnetic coupling is still significant at 1 K: spin-spin correlation around 3 for exciton occupation smaller than 0.3. We find that the interaction mediated by photon-polaritons is 10 times stronger than the one induced by a classical field for equal Rabi splitting.
Keywords:Localized spins, Semiconductor quantum dot, Microcavity, Single photon, Anisotropic exchange interaction
American Physical Society
info:eu-repo/semantics/article