Nonclassical light generation by Coulomb blockade of resonant tunneling

We show that the Coulomb blockade of resonant tunneling in semiconductor heterojunctions creates correlations between single-charge tunneling and single-photon emission events. When driven by a constant-current source, a mesoscopic p-i-i-i-n junction generates a regulated single-photon stream by single-electron-to-single-photon conversion. Under constant-voltage operation, the photon stream generated by the junction is antibunched and sub-Poissonian. The single-electron charging energy of the heterostructure has to exceed the width of the resonant subband and the characteristic energy of the thermal fluctuations for these correlations to be observable.