We theoretically demonstrate the generation of quadrature squeezed photons from a single quantum-dot with tuneable central frequency. The effects of exciton-phonon coupling on quadrature squeezing are also investigated.
We demonstrate the generation of frequency-tunable squeezed single photons from a continuous wave laser-driven single-quantum-dot system using a rigorous theoretical formalism, the so-called polaron master equation theory for accurately incorporating the exciton–phonon coupling. We investigate the squeezing for both resonant and off-resonant excitations and show that even for an appropriate off-resonant excitation, the degree of quadrature squeezing can be equal to or even greater than the maximum value obtained for a resonant excitation due to the increased purity of the quantum dot system. We further demonstrate, without losing the degree of squeezing, the tunability of the central frequency of squeezed photons by adjusting the detuning. We show that the detrimental effects due to the exciton–phonon coupling remain negligible up to the phonon bath temperature of 20 K and become quite appreciable beyond this temperature, particularly at higher phonon cutoff frequencies.
In this paper a mechanism for the generation of a squeezed state of light is theoretically presented. Due to coupling with excitons and via exciton-exciton interaction, a light beam propagating within a finite-size semiconductor sample is shown to evolve into a squeezed state. Based on an effective bosonic Hamiltonian, which is obtained from the original fermionic one, a detailed derivation of the photon quadrature variances is presented and dependences of the photon squeezing on both the extrinsic and intrinsic parameters are analyzed.
Squeezed light is a particularly useful quantum resource, which finds broad applications in quantum information processing, quantum metrology and sensing, and biological measurements. Here we show how to produce squeezed light exploiting the strong exciton–phonon nonlinear interaction in a semiconductor microcavity. The semiconductor microcavity is embedded with a quantum well, which supports both linear and nonlinear interactions among excitons, phonons, and cavity photons. We show that the strong exciton–phonon deformation potential interaction can induce a quadrature-squeezed cavity output field, and further reveal an important role of the exciton–photon coupling in engineering the squeezing spectrum and improving the robustness of the squeezing against thermal noise. Our results indicate that substantial optical squeezing in a broad band, up to tens of gigahertz, can be achieved using currently available parameters.
We propose efficient frequency-tunable single-photon sources using stimulated frequency downconversion occurring directly in the quantum dot (QD) inside a microcavity. This microcavity should be designed not for the exciton frequency in the QD but for the target frequency that is set by the difference between the exciton resonance and the stimulating laser energies. This frequency downconversion arises from the second-order nonlinear interaction of an exciton (bright or dark) and a light-hole exciton in the stimulating laser field. We present an analytical model for such a process and evaluate its efficiency for a widely sought-after single-photon source for the C-band telecommunications.