title: Injection Locking of a Semiconductor Double Quantum Dot Micromaser.
abstract: Emission linewidth is an important figure of merit for masers and lasers. We recently demonstrated a semiconductor double quantum dot (DQD) micromaser where photons are generated through single electron tunneling events. Charge noise directly couples to the DQD energy levels, resulting in a maser linewidth that is more than 100 times larger than the Schawlow-Townes prediction. Here we demonstrate a linewidth narrowing of more than a factor 10 by locking the DQD emission to a coherent tone that is injected to the input port of the cavity. We measure the injection locking range as a function of cavity input power and show that it is in agreement with the Adler equation. The position and amplitude of distortion sidebands that appear outside of the injection locking range are quantitatively examined. Our results show that this unconventional maser, which is impacted by strong charge noise and electron-phonon coupling, is well described by standard laser models.
authors.affiliation: Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Y-Y
authors.initials: YY
authors.lastname: Liu
authors.affiliation: Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: J
authors.initials: J
authors.lastname: Stehlik
authors.affiliation: Joint Quantum Institute, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA; Joint Center for Quantum Information and Computer Science, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Gullans
authors.affiliation: Joint Quantum Institute, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA; Joint Center for Quantum Information and Computer Science, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Taylor
authors.affiliation: Department of Physics, Princeton University, Princeton, New Jersey 08544, USA; Department of Physics, University of California, Santa Barbara, California 93106, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Petta