U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Michael Stewart (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 1 - 25 of 42

Statistical study and parallelization of multiplexed single-electron sources

September 9, 2024
Author(s)
S Norimoto, P See, N Schoinas, I Rungger, Tommy Boykin, Michael Stewart, J. P. Griffiths, C. Chen, D. A. Ritchie, M. Kataoka
Increasing electric current from a single-electron source is a main challenge in an effort to establish the standard of the ampere defined by the fixed value of the elementary charge e and operation frequency f . While the current scales with f , due to an

Multi-scale alignment to buried atom-scale devices using Kelvin probe force microscopy

February 24, 2024
Author(s)
Pradeep Namboodiri, Jonathan Wyrick, Gheorghe Stan, Xiqiao Wang, Fan Fei, Ranjit Kashid, Scott Schmucker, Richard Kasica, Bryan Barnes, Michael Stewart, Richard M. Silver
Fabrication of quantum devices by atomic scale patterning with a Scanning Tunneling Microscope (STM) has led to the development of single/few atom transistors, few-donor/quantum dot devices for spin manipulation and arrayed few-donor devices for analog

Alternatives to aluminum gates for silicon quantum devices: Defects and strain

September 15, 2021
Author(s)
Ryan Stein, Zachary Barcikowski, Sujitra Pookpanratana, Joshua M. Pomeroy, Michael Stewart
Gate-defined quantum dots (QD) benefit from the use of small grain size metals for gates materials because it aids in shrinking the device dimensions. However, it is not clear what differences arise with respect to process-induced defect densities and

Reduction of charge offset drift using plasma oxidized aluminum in SETs

October 26, 2020
Author(s)
Yanxue Hong, Ryan Stein, Michael Stewart, Neil M. Zimmerman, Joshua M. Pomeroy
Aluminum oxide (AlOx)-based single-electron transistors (SETs) fabricated in ultra-high vacuum (UHV) chambers using in situ plasma oxidation show excellent stabilities over more than a week, enabling applications as tunnel barriers, capacitor dielectrics

The effect of strain on tunnel barrier height in silicon quantum devices

July 13, 2020
Author(s)
Ryan Stein, Michael Stewart
Semiconductor quantum dot (QD) devices experience a modulation of the band structure at the edge of lithographically defined gates due to mechanical strain. This modulation can play a prominent role in the device behavior at low temperatures, where QD

Electron-electron interactions in low-dimensional Si:P delta layers

June 15, 2020
Author(s)
Joseph Hagmann, Xiqiao Wang, Ranjit Kashid, Pradeep Namboodiri, Jonathan Wyrick, Scott W. Schmucker, Michael Stewart, Richard M. Silver, Curt A. Richter
Key to producing quantum computing devices based on the atomistic placement of dopants in silicon by scanning tunneling microscope (STM) lithography is the formation of embedded highly doped Si:P delta layers (δ-layers). This study investigates the

Atomic-scale control of tunneling in donor-based devices

May 11, 2020
Author(s)
Xiqiao Wang, Jonathan E. Wyrick, Ranjit V. Kashid, Pradeep N. Namboodiri, Scott W. Schmucker, Andrew Murphy, Michael D. Stewart, Richard M. Silver
Atomically precise donor-based quantum devices are a promising candidate for scalable solid- state quantum computing. Atomically precise design and implementation of the tunnel coupling in these devices is essential to realize gate-tunable exchange

Low-resistance, high-yield electrical contacts to atom scale Si:P devices using palladium silicide

March 29, 2019
Author(s)
Scott W. Schmucker, Pradeep Namboodiri, Ranjit Kashid, Xiqiao Wang, Binhui Hu, Jonathan Wyrick, Alline Myers, Joshua D. Schumacher, Richard M. Silver, Michael Stewart
Scanning tunneling microscopy (STM) enables the fabrication of 2-D delta-doped structures in Si with atomistic precision, with applications from tunnel field effect transistors to qubits. The combination of a very small contact area and the restrictive

Machine Learning techniques for state recognition and auto-tuning in quantum dots

January 20, 2019
Author(s)
Sandesh Kalantre, Justyna Zwolak, Stephen Ragole, Xingyao Wu, Neil M. Zimmerman, Michael Stewart, Jacob Taylor
Recent progress in building large-scale quantum devices for exploring quantum computing and simulation paradigms has relied upon effective tools for achieving and maintaining good experimental parameters, i.e. tuning up devices. In many cases, including in

Effect of device design on charge offset drift in Si/SiO2 single electron devices

October 9, 2018
Author(s)
Binhui Hu, Erick Ochoa, Daniel Sanchez, Justin K. Perron, Neil M. Zimmerman, Michael Stewart
We have measured the low-frequency time instability known as charge offset drift of Si/SiO2 single electron devices (SEDs) with and without an overall poly-Si top gate. We find that SEDs with a poly-Si top gate have significantly less charge offset drift

STM patterned nanowire measurements using photolithographically defined implants in Si(100)

January 29, 2018
Author(s)
Aruna N. Ramanayaka, Hyun Soo Kim, Ke Tang, Xiqiao Wang, Richard M. Silver, Michael D. Stewart, Joshua M. Pomeroy
Using photolithographically defined implant wires for electrical connections, we demonstrate measurement of a scanning tunneling microscope (STM) patterned nanoscale electronic device on Si(100), eliminating the onerous alignment procedures and electron

Quantifying Atom-scale Dopant Movement and Electrical Activation in Si:P Monolayers

January 26, 2018
Author(s)
Xiqiao Wang, Joseph A. Hagmann, Pradeep N. Namboodiri, Jonathan E. Wyrick, Kai Li, Roy E. Murray, Frederick Meisenkothen, Alline F. Myers, Michael D. Stewart, Richard M. Silver
Doped semiconductor structures with ultra-sharp dopant confinement, minimal lattice defects, and high carrier concentrations are essential attributes in the development of both ultra- scaled conventional semiconductor devices and emerging all-silicon