Single self-assembled InAs/GaAs quantum dots in photonic nanostructures: the role of nanofabrication

Published: June 13, 2018


Jin Liu, Kumarasiri Konthasinghe, Marcelo I. Davanco, John R. Lawall, Vikas Anant, Varun B. Verma, Richard P. Mirin, Jin Dong Song, Ben Ma, Ze Sheng Chen, Hai Qiao Ni, Zhi Chuan Niu, Kartik A. Srinivasan


Single self-assembled InAs/GaAs quantum dots are a promising solid-state quantum technology, with vacuum Rabi splitting, single-photon-level nonlinearities, and bright, pure, and indistinguishable single-photon generation having been demonstrated. In such applications, nanofabrication is used to create structures in which the quantum dot preferentially interacts with strongly-confined optical modes. An open question is the extent to which such nanofabrication may also have an adverse influence, through the creation of traps and surface states that could induce blinking, spectral diffusion, and dephasing. Here, we use photoluminescence imaging to locate the positions of single InAs/GaAs quantum dots with respect to alignment marks with < 5 nm uncertainty, allowing us to measure their behavior before and after fabrication. We track the quantum dot emission linewidth and photon statistics as a function of distance from an etched surface, and find that the linewidth is significantly broadened for etched surfaces within a couple hundred nanometers of the quantum dot, while blinking at a level that appreciably reduces the quantum dot radiative efficiency is unobserved. We also show that atomic layer deposition can serve as a tool to stabilize spectral diffusion of the quantum dot emission, and partially recover its linewidth.
Citation: Physical Review Applied
Volume: 9
Issue: 6
Pub Type: Journals
Created June 13, 2018, Updated July 23, 2018