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Displaying 1 - 15 of 15

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

Experimental realization of an extended Fermi-Hubbard model using a 2D lattice of dopant-based quantum dots

November 11, 2022
Author(s)
Richard M. Silver, Jonathan Wyrick, Xiqiao Wang, Ranjit Kashid, Garnett W. Bryant, Albert Rigosi, Pradeep Namboodiri, Ehsan Khatami
The Hubbard model is one of the primary models for understanding the essential many-body physics in condensed matter systems such as Mott insulators and cuprate high-Tc superconductors. Due to the long-range Coulomb interactions, accessible low

Enhanced Atomic Precision Fabrication by Adsorption of Phosphine into Engineered Dangling Bonds on H-Si Using STM and DFT

November 1, 2022
Author(s)
Jonathan Wyrick, Xiqiao Wang, Pradeep Namboodiri, Ranjit Kashid, Fan Fei, Joseph Fox, Richard M. Silver
Doping of Si using the scanning probe technique of hydrogen depassivation lithography has been shown to enable placing and positioning small numbers of P atoms with nanometer accuracy. Several groups have now used this capability to build devices that

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

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

Weak localization thickness measurements of embedded phosphorus delta layers in silicon produced by PH3 dosing

January 23, 2018
Author(s)
Joseph A. Hagmann, Xiqiao Wang, Pradeep N. Namboodiri, Jonathan E. Wyrick, Roy E. Murray, Michael D. Stewart, Richard M. Silver
The key building blocks for devices based on the deterministic placement of dopants in silicon are the formation of phosphorus dopant monolayers and the overgrowth of high quality crystalline Si. Lithographically defined dopant delta-layers can be formed

Towards single atom devices for quantum information and metrology: weak localization in embedded phosphorus delta layers in silicon

June 29, 2017
Author(s)
Joseph A. Hagmann, Xiqiao Wang, Pradeep N. Namboodiri, Jonathan E. Wyrick, Roy E. Murray, Michael D. Stewart, Richard M. Silver, Curt A. Richter
The key building block for devices based on the deterministic placement of dopants in silicon is the formation of phosphorus dopant monolayers and the overgrowth of high quality crystalline Si. Lithographically defined dopant delta-layers can be formed

Atomically precise device fabrication

December 7, 2016
Author(s)
Joseph A. Hagmann, Xiqiao Wang, Pradeep N. Namboodiri, Richard M. Silver, Curt A. Richter
An improved capacity to control matter at the atomic scale is central to the advancement of nanotechnology. The complementary metal-oxide-semiconductor (CMOS) devices that power existing computing technology, which continue to scale down in size as

Silicon epitaxy on H-terminated Si (100) surfaces at 250deg C

March 31, 2016
Author(s)
Xiao Deng, Pradeep N. Namboodiri, Kai Li, Xiqiao Wang, Gheorghe Stan, Alline F. Myers, Xinbin Cheng, Tongbao Li, Richard M. Silver
Silicon on silicon growth at low temperatures has become increasing important due to its use to encapsulate buried nanoscale dopant devices. The performance of atomic scale devices is fundamentally affected by the quality of the silicon matrix in which the