title: Four-wave mixing signal enhancement and optical bistability of a hybrid metal nanoparticle-quantum dot molecule in a nanomechanical resonator.
abstract: We investigate theoretically four-wave mixing (FWM) response and optical bistability (OB) in a hybrid nanosystem composed of a metal nanoparticle (MNP) and a semiconductor quantum dot (SQD) coupled to a nanomechanical resonator (NR). It is shown that the FWM signal is enhanced by more than three orders of magnitude as compared to that of the system without exciton-phonon interaction, and the FWM signal can also be suppressed significantly and broadened due to the exciton-plasmon interaction. As the MNP couples strongly with the SQD, the bistable FWM response can be achieved by adjusting the SQD-MNP distance and the pumping intensity. For a given pumping constant and a fixed SQD-MNP distance, the enhanced exciton-phonon interaction can promote the occurrence of bistability. Our findings not only present a feasible way to detect the spacing between two nanoparticles, but also hold promise for developing quantum switches and nanoscale rulers.
authors.forename: Jian-Bo
authors.initials: JB
authors.lastname: Li
authors.forename: Shan
authors.initials: S
authors.lastname: Liang
authors.forename: Si
authors.initials: S
authors.lastname: Xiao
authors.forename: Meng-Dong
authors.initials: MD
authors.lastname: He
authors.forename: Nam-Chol
authors.initials: NC
authors.lastname: Kim
authors.forename: Li-Qun
authors.initials: LQ
authors.lastname: Chen
authors.forename: Gui-Hong
authors.initials: GH
authors.lastname: Wu
authors.forename: Yu-Xiang
authors.initials: YX
authors.lastname: Peng
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Luo
authors.forename: Ze-Ping
authors.initials: ZP
authors.lastname: Guo