Nonlocal Nuclear Spin Quieting in Quantum Dot Molecules: Optically Induced Extended Two-Electron Spin Coherence Time

Colin M. Chow, Aaron M. Ross, Danny Kim, Daniel Gammon, Allan S. Bracker, L. J. Sham, and Duncan G. Steel

Phys. Rev. Lett. 117, 077403 – Published 12 August 2016

Abstract

We demonstrate the extension of coherence between all four two-electron spin ground states of an InAs quantum dot molecule (QDM) via nonlocal suppression of nuclear spin fluctuations in two vertically stacked quantum dots (QDs), while optically addressing only the top QD transitions. Long coherence times are revealed through dark-state spectroscopy as resulting from nuclear spin locking mediated by the exchange interaction between the QDs. Line shape analysis provides the first measurement of the quieting of the Overhauser field distribution correlating with reduced nuclear spin fluctuations.

Received 15 December 2015

DOI:https://doi.org/10.1103/PhysRevLett.117.077403

Physics Subject Headings (PhySH)

Nonlinear optics Quantum information architectures & platforms Quantum optics with artificial atoms Semiconductor quantum optics

Double quantum dots Quantum dots

Magneto-optical Kerr effect Optical absorption spectroscopy

Condensed Matter, Materials & Applied PhysicsAtomic, Molecular & OpticalQuantum Information, Science & Technology

Authors & Affiliations

Colin M. Chow^1,2, Aaron M. Ross¹, Danny Kim^3,5, Daniel Gammon³, Allan S. Bracker³, L. J. Sham⁴, and Duncan G. Steel^1,2

¹H. M. Randall Laboratory of Physics, University of Michigan, Ann Arbor, Michigan 48104, USA
²Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109, USA
³Naval Research Laboratory, Washington D.C. 20375, USA
⁴Department of Physics, University of California San Diego, La Jolla, California 92093, USA
⁵HRL Laboratories, LLC, 3011 Malibu Canyon Road, Malibu, California 90265, USA