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: Manuel Castellanos Beltran (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 26 - 39 of 39

Planarized process for single-flux-quantum circuits with self-shunted Nb/NbxSi1-x/Nb Josephson junctions

February 18, 2019
Author(s)
David I. Olaya, Manuel C. Castellanos Beltran, Javier Pulecio, John P. Biesecker, Soroush Khadem, Theodore Lewitt, Peter F. Hopkins, Paul D. Dresselhaus, Samuel P. Benz
We describe the single-flux-quantum (SFQ) circuit fabrication process employed at NIST's Boulder Microfabrication Facility. The process includes four superconducting metal layers, one palladium-gold resistor layer, and a contact pad layer. Chemical

RF waveform synthesizers with quantum-based voltage accuracy for communications metrology

February 11, 2019
Author(s)
Peter F. Hopkins, Justus A. Brevik, Manuel C. Castellanos Beltran, Nathan E. Flowers-Jacobs, Anna E. Fox, David I. Olaya, Christine A. Donnelly, Paul D. Dresselhaus, Samuel P. Benz
We report on NIST’s development of Josephson junction-based programmable reference sources to synthesize quantum-accurate, spectrally-pure waveforms for characterizing and improving next generation communication devices and systems. The goal is to provide

Stacked Josephson Junctions as inductors for SFQ circuits

February 11, 2019
Author(s)
Manuel C. Castellanos Beltran, David I. Olaya, Adam J. Sirois, Paul D. Dresselhaus, Samuel P. Benz, Peter F. Hopkins
In order for Single Flux Quantum (SFQ) circuits to be scaled to densities needed for large-scale integration, typical lithographically-patterned circuit components should be made to be as compact as possible. In this work, we characterize the performance

Superconducting optoelectronic networks III: synaptic plasticity

July 5, 2018
Author(s)
Jeffrey M. Shainline, Adam N. McCaughan, Sonia M. Buckley, Christine A. Donnelly, Manuel C. Castellanos Beltran, Michael L. Schneider, Richard P. Mirin, Sae Woo Nam
As a means of dynamically reconfiguring the synaptic weight of a superconducting optoelectronic loop neuron, a superconducting flux storage loop is inductively coupled to the synaptic current bias of the neuron. A standard flux memory cell is used to

Superconducting optoelectronic networks II: receiver circuits

April 6, 2018
Author(s)
Jeffrey M. Shainline, Sonia M. Buckley, Adam N. McCaughan, Manuel C. Castellanos Beltran, Christine A. Donnelly, Michael L. Schneider, Richard P. Mirin, Sae Woo Nam
Circuits using superconducting single-photon detectors and Josephson junctions to perform signal reception, synaptic weighting, and integration are investigated. The circuits convert photon-detection events into flux quanta, the number of which is

Scalable, High-Speed, Digital Single-Flux-Quantum Circuits at NIST

June 11, 2017
Author(s)
Pete Hopkins, Manuel Castellanos Beltran, Christine A. Donnelly, Paul Dresselhaus, David Olaya, Adam Sirois, Samuel P. Benz
We describe NIST's capabilities for designing and fabricating niobium-based single-flux quantum (SFQ) digital and mixed-signal circuits and show test results of our first circuits. We have assembled a package of software design tools that are readily

Tunable Resonant and Nonresonant Interactions between a Phase Qubit and LC Resonator

March 26, 2014
Author(s)
Michael S. Allman, Jed D. Whittaker, Manuel C. Castellanos Beltran, Katarina Cicak, Fabio C. Da Silva, Michael DeFeo, Florent Q. Lecocq, Adam J. Sirois, John D. Teufel, Jose A. Aumentado, Raymond W. Simmonds
We use a flux-biased radio frequency superconducting quantum interference device (rf SQUID) with an embedded flux-biased direct current SQUID to generate strong resonant and nonresonant tunable interactions between a phase qubit and a lumped-element