Microwave engineering for semiconductor quantum dots in a cQED architecture
Abstract
We develop an engineered microwave environment for coupling high Q superconducting resonators to quantum dots using a multilayer fabrication stack for dot control wiring. Analytical and numerical models are presented, which show that high resonator quality factors can be attained by either minimizing the parasitic coupling capacitance to the leads or creating a low effective environmental impedance at the cavity frequency. We implement the later approach by fabricating low characteristic impedance (Zg≈10 Ω) microstrips on-chip for the dot bias wiring and show resonator quality factors of 8140 that can be attained without the addition of explicit filtering. Using this approach, we demonstrate single electron occupation in double and triple dots detected via dipole or quadrupole coupling to a superconducting resonator. Additionally, by using multilayer fabrication, we are able to improve ground plane integrity and keep microwave crosstalk below −20 dB out to 18 GHz while maintaining high wire density, which will be necessary for future circuit quantum electrodynamics quantum dot processors.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Aug 24, 2020
- Source ID
- 10.1063/5.0016248
Entities
People
- J. P. Dodson
- L. F. Edge
- M. A. Eriksson
- Mark Friesen
- Nathan Holman
- R. Mcdermott
- S. N. Coppersmith
Organizations
- Army Research Office
- HRL Laboratories
- National Science Foundation
- Office of Naval Research
- University of New South Wales
- University of Wisconsin–Madison