Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Electronic Enhancement of the Exciton Coherence Time in Charged Quantum Dots

Published

Author(s)

Galan A. Moody, Corey A. McDonald, Ari D. Feldman, Todd E. Harvey, Richard P. Mirin, Kevin L. Silverman

Abstract

Minimizing decoherence due to coupling of a quantum system to its fluctuating environment is at the forefront of quantum information and photonics research. Nature sets the ultimate limit, however, given by the strength of the system’s coupling to the electromagnetic field. Here, we establish the ability to electronically control this coupling and enhance the optical coherence time of the charged exciton transition in quantum dots embedded in a photonic waveguide. By manipulating the electron and hole wavefunctions through an applied lateral electric field, we increase the coherence time from ~1.4 ns to ~2.7 ns. Numerical calculations reveal that longer coherence arises from the separation of charge carriers by up to ~6 nm, which leads to a 30% weaker transition dipole moment. The ability to electrostatically control the coherence time and transition dipole moment opens new avenues for quantum communication and novel coupling schemes between distant qubits.
Citation
Physical Review Letters

Keywords

quantum dot, nonlinear spectroscopy, homogeneous linewidth, electric field
Created October 19, 2015, Updated February 19, 2017