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: Pradeep Namboodiri (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 1 - 25 of 30

Optical Studies of Silicon Color Centers and CC-LEDs for Consideration as Telecom Quantum Light Sources

October 29, 2024
Author(s)
Nikki Ebadollahi, Pradeep Namboodiri, Vijin Kizhake Veetil, Marcelo Davanco, Kartik Srinivasan, Aaron Katzenmeyer, Matthew Pelton, Joshua Pomeroy
We synthesized and studied color centers on silicon-on-insulator wafers with photoluminescence mapping and spectroscopy, and fabricated silicon W- and G- color center LEDs towards electrically-pumped single photon sources.

Design, modeling, and fabrication of high frequency Oersted lines for electron spin manipulation in silicon based quantum devices

October 25, 2024
Author(s)
Pradeep Namboodiri, Mark-yves Gaunin, Alessandro Restelli, Ranjit Kashid, Xiqiao Wang, Fan Fei, Brian Courts, FNU Utsav, Vijith Kamalon Pulikodan, Jonathan Wyrick, Richard M. Silver
Coherent manipulation of electron spins is one of the central problems of silicon-based quantum computing efforts. Electron spin resonance (ESR) lines, or Oersted lines, allow high frequency RF pulses to induce an electromagnetic field that drives Rabi

DC to GHz measurements of a near-ideal 2D material: P+ monolayers

March 8, 2024
Author(s)
Neil M. Zimmerman, Antonio Levy, Pradeep Namboodiri, Joshua M. Pomeroy, Xiqiao Wang, Joseph Fox, Richard M. Silver
P+ monolayers in Si are of great scientific and technological interest, both intrinsically as a material in the "ideal vacuum" of crystalline Si, and because they are showing great promise as qubits of electron and nuclear spin. The GHz complex

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

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

Pattern Transfer of Hydrogen Depassivation Lithography Patterns into Silicon with Atomically Traceable Placement and Size Control

July 17, 2014
Author(s)
Josh Ballard, Stephen McDonnell, Don Dick, Maia Bischof, Joseph Fu, D Jaeger, James Owen , w Owen, Justin Alexander, Udi Fuchs, Pradeep Namboodiri, Kai Li, John Randall, Robert Wallace, Yves Chabal, Richard Reidy, Richard M. Silver
Reducing the scale of etched nanostructures below the 10 nm range eventually will require an atomic scale understanding of the masks being used in order to maintain exquisite control over both feature size and feature density. Here, we demonstrate a method

Size Measurement of Nanoparticles Using Atomic Force Microscopy, ASTM E2859-11

January 2, 2012
Author(s)
Jaroslaw Grobelny, Frank W. DelRio, Pradeep Namboodiri, Doo-In Kim, Vincent A. Hackley, Robert F. Cook
The purpose of this document is to provide guidance on the quantitative application of atomic force microscopy (AFM) to determine the size of nanoparticles2 deposited in dry form on flat substrates using height (z-displacement) measurement. Unlike electron

Controlling Formation of Atomic Step Morphology on Micro-patterned Si (100)

August 9, 2011
Author(s)
Kai Li, Pradeep Namboodiri, Sumanth B. Chikkamaranahalli, Gheorghe Stan, Ravikiran Attota, Joseph Fu, Richard M. Silver
Micro scale features are fabricated on Si (100) surfaces using lithographic techniques and then thermally processed in an ultra high vacuum (UHV) environment. Samples are flash heated at 1200 °C and further annealed at 1050 °C for 18 hours. The surface

Size Measurement of Nanoparticles using Atomic Force Microscopy

January 1, 2011
Author(s)
Jaroslaw Grobelny, Frank W. DelRio, Pradeep Namboodiri, Doo-In Kim, Vincent A. Hackley, Robert F. Cook
This chapter outlines procedures for sample preparation and the determination of nanoparticle size using atomic force microscopy (AFM). To start, procedures for dispersing gold nanoparticles on various surfaces such that they are suitable for imaging and

Size Measurement of Nanoparticles using Atomic Force Microscopy

October 1, 2009
Author(s)
Jaroslaw Grobelny, Frank W. DelRio, Pradeep Namboodiri, Doo-In Kim, Vincent A. Hackley, Robert F. Cook
In this assay protocol, procedures for dispersing gold nanoparticles on various surfaces such that they are suitable for imaging and height measurement via intermittent contact mode AFM are first described. The procedures for AFM calibration and operation