skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Fabrication of quantum dots in undoped Si/Si 0.8Ge 0.2 heterostructures using a single metal-gate layer

Abstract

Enhancement-mode Si/SiGe electron quantum dots have been pursued extensively by many groups for their potential in quantum computing. Most of the reported dot designs utilize multiple metal-gate layers and use Si/SiGe heterostructures with Ge concentration close to 30%. Here, we report the fabrication and low-temperature characterization of quantum dots in the Si/Si 0.8Ge 0.2 heterostructures using only one metal-gate layer. We find that the threshold voltage of a channel narrower than 1 μm increases as the width decreases. The higher threshold can be attributed to the combination of quantum confinement and disorder. We also find that the lower Ge ratio used here leads to a narrower operational gate bias range. The higher threshold combined with the limited gate bias range constrains the device design of lithographic quantum dots. We incorporate such considerations in our device design and demonstrate a quantum dot that can be tuned from a single dot to a double dot. Furthermore, the device uses only a single metal-gate layer, greatly simplifying device design and fabrication.

Authors:
ORCiD logo [1];  [1]; ORCiD logo [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1];  [1]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
Work for Others (WFO); USDOE
OSTI Identifier:
1320515
Report Number(s):
SAND2016-8268J
Journal ID: ISSN 0003-6951; APPLAB; 646874
Grant/Contract Number:  
AC04-94AL85000
Resource Type:
Accepted Manuscript
Journal Name:
Applied Physics Letters
Additional Journal Information:
Journal Volume: 109; Journal Issue: 9; Journal ID: ISSN 0003-6951
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Lu, T. M., Gamble, J. K., Muller, R. P., Nielsen, E., Bethke, D., Ten Eyck, G. A., Pluym, T., Wendt, J. R., Dominguez, J., Lilly, M. P., Carroll, M. S., and Wanke, M. C. Fabrication of quantum dots in undoped Si/Si0.8Ge0.2 heterostructures using a single metal-gate layer. United States: N. p., 2016. Web. doi:10.1063/1.4961889.
Lu, T. M., Gamble, J. K., Muller, R. P., Nielsen, E., Bethke, D., Ten Eyck, G. A., Pluym, T., Wendt, J. R., Dominguez, J., Lilly, M. P., Carroll, M. S., & Wanke, M. C. Fabrication of quantum dots in undoped Si/Si0.8Ge0.2 heterostructures using a single metal-gate layer. United States. doi:10.1063/1.4961889.
Lu, T. M., Gamble, J. K., Muller, R. P., Nielsen, E., Bethke, D., Ten Eyck, G. A., Pluym, T., Wendt, J. R., Dominguez, J., Lilly, M. P., Carroll, M. S., and Wanke, M. C. Mon . "Fabrication of quantum dots in undoped Si/Si0.8Ge0.2 heterostructures using a single metal-gate layer". United States. doi:10.1063/1.4961889. https://www.osti.gov/servlets/purl/1320515.
@article{osti_1320515,
title = {Fabrication of quantum dots in undoped Si/Si0.8Ge0.2 heterostructures using a single metal-gate layer},
author = {Lu, T. M. and Gamble, J. K. and Muller, R. P. and Nielsen, E. and Bethke, D. and Ten Eyck, G. A. and Pluym, T. and Wendt, J. R. and Dominguez, J. and Lilly, M. P. and Carroll, M. S. and Wanke, M. C.},
abstractNote = {Enhancement-mode Si/SiGe electron quantum dots have been pursued extensively by many groups for their potential in quantum computing. Most of the reported dot designs utilize multiple metal-gate layers and use Si/SiGe heterostructures with Ge concentration close to 30%. Here, we report the fabrication and low-temperature characterization of quantum dots in the Si/Si0.8Ge0.2 heterostructures using only one metal-gate layer. We find that the threshold voltage of a channel narrower than 1 μm increases as the width decreases. The higher threshold can be attributed to the combination of quantum confinement and disorder. We also find that the lower Ge ratio used here leads to a narrower operational gate bias range. The higher threshold combined with the limited gate bias range constrains the device design of lithographic quantum dots. We incorporate such considerations in our device design and demonstrate a quantum dot that can be tuned from a single dot to a double dot. Furthermore, the device uses only a single metal-gate layer, greatly simplifying device design and fabrication.},
doi = {10.1063/1.4961889},
journal = {Applied Physics Letters},
number = 9,
volume = 109,
place = {United States},
year = {2016},
month = {8}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record

Citation Metrics:
Cited by: 1 work
Citation information provided by
Web of Science

Save / Share:

Works referenced in this record:

A silicon-based nuclear spin quantum computer
journal, May 1998


A reconfigurable gate architecture for Si/SiGe quantum dots
journal, June 2015

  • Zajac, D. M.; Hazard, T. M.; Mi, X.
  • Applied Physics Letters, Vol. 106, Issue 22
  • DOI: 10.1063/1.4922249

Quantum control and process tomography of a semiconductor quantum dot hybrid qubit
journal, July 2014


Electron transport through double quantum dots
journal, December 2002

  • van der Wiel, W. G.; De Franceschi, S.; Elzerman, J. M.
  • Reviews of Modern Physics, Vol. 75, Issue 1
  • DOI: 10.1103/RevModPhys.75.1

Isotopically enhanced triple-quantum-dot qubit
journal, May 2015


Enhancement-mode buried strained silicon channel quantum dot with tunable lateral geometry
journal, July 2011

  • Lu, T. M.; Bishop, N. C.; Pluym, T.
  • Applied Physics Letters, Vol. 99, Issue 4
  • DOI: 10.1063/1.3615288

Upper limit of two-dimensional electron density in enhancement-mode Si/SiGe heterostructure field-effect transistors
journal, October 2011

  • Lu, T. M.; Lee, C. -H.; Huang, S. -H.
  • Applied Physics Letters, Vol. 99, Issue 15
  • DOI: 10.1063/1.3652909

High-mobility Si and Ge structures
journal, December 1997


Quantum computation with quantum dots
journal, January 1998


Silicon quantum electronics
journal, July 2013

  • Zwanenburg, Floris A.; Dzurak, Andrew S.; Morello, Andrea
  • Reviews of Modern Physics, Vol. 85, Issue 3
  • DOI: 10.1103/RevModPhys.85.961

Observation of two-dimensional electron gas in a Si quantum well with mobility of 1.6×106 cm2/Vs
journal, May 2009

  • Lu, T. M.; Tsui, D. C.; Lee, C. -H.
  • Applied Physics Letters, Vol. 94, Issue 18
  • DOI: 10.1063/1.3127516