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Displaying 76 - 100 of 204

Surface science for improved ion traps

September 30, 2013
Author(s)
David P. Pappas, Dustin Hite, Andrew C. Wilson, David T. Allcock, David J. Wineland, Dietrich Leibfried, Yves Colombe
Trapped ions are sensitive to electric-field noise from trap-electrode surfaces. This noise has been an obstacle to progress in trapped-ion quantum information processing (QIP) experiments for more than a decade. It causes motional heating of the ions, and

Micro-fabricated stylus ion trap

August 7, 2013
Author(s)
Kyle S. McKay, Christian L. Arrington, Ehren D. Baca, Jonathan J. Coleman, Yves Colombe, Patrick Finnegan, Dustin A. Hite, Andrew E. Hollowell, Robert Jordens, John D. Jost, Dietrich G. Leibfried, Adam M. Rowen, Ulrich J. Warring, David J. Wineland, David P. Pappas, Andrew C. Wilson
An electroformed, three-dimensional stylus Paul trap was designed to confine a single atomic ion for use as a sensor to probe the electric-field noise of proximate surfaces. The trap was microfabricated with the UV-LIGA technique to reduce the distance of

Optimized superconducting detectors using the proximity effect in Ti/TiN multilayers

June 14, 2013
Author(s)
David P. Pappas, Michael R. Vissers, Jiansong Gao, Martin O. Sandberg, David S. Wisbey, Kent D. Irwin
We apply the superconducting proximity effect in TiN/Ti multi-layers films to tune the critical temperature, $T_C$ (to within 10 mK) with high uniformity (less than 15 mK spread) across a 75 mm wafer. Reproducible $T_C$'s are obtained from 0.8 - 2.5 K

Radiation-suppressed superconducting quantum bit in a planar geometry

February 19, 2013
Author(s)
Martin O. Sandberg, Tomas A. Ohki, Jose A. Aumentado, Martin P. Weides, David P. Pappas
We present a superconducting transmon qubit circuit design based on large, coplanar capacitor plates and a microstrip resonator. The microstrip geometry, with the ground plane on the back, enhances access to the circuit for state preparation and

Dual-polarization sensitive MKIDs for far infrared astrophysics

December 12, 2012
Author(s)
Johannes Hubmayr, James A. Beall, Daniel T. Becker, Hsiao-Mei Cho, Brad Dober, Mark Devlin, Anna E. Fox, Dale Li, Michael D. Niemack, David P. Pappas, Leila R. Vale, Kent D. Irwin, Gene C. Hilton
We present the design for arrays of dual-polarization sensitive, superconducting sensors for far infrared astrophysics. Each pixel is feedhorn-coupled and consists of orthogonal, lumped-element kinetic inductance detectors (LEKIDs) both fabricated in the

A titanium-nitride near-infrared kinetic inductance photon-counting detector and its anomalous electrodynamics

October 1, 2012
Author(s)
Martin O. Sandberg, Fabio C. da Silva, Kent D. Irwin, David P. Pappas, Sae Woo Nam, David Wisbey, Ben Mazin, Seth Meeker, Jonas Zmuidzinas, Henry G. Leduc
We demonstrate single-photon counting at 1550 nm with titanium-nitride (TiN) microwave kinetic inductancedetectors. Full-width-at-half-maximum energy resolution of 0.4 eV is achieved. 0-, 1-, 2- photon events are resolved and shown to follow Poisson

Characterization and In-situ Monitoring of Sub-stoichiometric Adjustable TC Titanium Nitride Growth

September 21, 2012
Author(s)
Michael R. Vissers, Jiansong Gao, Jeffrey S. Kline, Martin O. Sandberg, Martin P. Weides, David S. Wisbey, David P. Pappas
The structural and electrical properties of Ti-N films deposited by reactive sputtering depend on their growth parameters, in particular the Ar:N2 gas ratio. We show that the nitrogen percentage changes the crystallographic phase of the film progressively

100-Fold Reduction of Electric-Field Noise in an Ion Trap Cleanded with In Situ Argon-Ion-Beam Bombardment

September 7, 2012
Author(s)
Dustin Hite, Yves Colombe, Andrew C. Wilson, Kenton R. Brown, Ulrich J. Warring, Robert Jordens, John D. Jost, David P. Pappas, Dietrich Leibfried, David J. Wineland, Kyle McKay
Anomalous heating of trapped atomic ions is a major obstacle to their use as quantum bits in scalable quantum computers. The physical origin of this electric field noise is not fully understood, but experimental evidence suggests that it emanates from the

Etch induced microwave losses in titanium nitride superconducting resonators

June 25, 2012
Author(s)
Martin O. Sandberg, Jeffrey S. Kline, Martin P. Weides, David S. Wisbey, David P. Pappas
We have investigated the correlation between the microwave loss and patterning method for coplanar waveguide titanium nitride resonators fabricated on silicon wafers. Three different methods were investigated: fluorine- and chlorine-based reactive ion

Reduced microwave loss in trenched superconducting coplanar waveguides

February 20, 2012
Author(s)
Michael R. Vissers, Jeffrey S. Kline, Jiansong Gao, David S. Wisbey, David P. Pappas
Low loss TiN resonators were fabricated on 3" intrinsic Si substrates. By exploiting the etch rate anisotropy in a parallel plate reactive ion etch, otherwise identical coplanar waveguides with gaps of varying depth were created in the same TiN film within

Two Level System Loss in Superconducting Microwave Resonators

January 13, 2011
Author(s)
David P. Pappas, Michael R. Vissers, David S. Wisbey, Jeffrey S. Kline, Jiansong Gao
High quality factor, i.e. low loss, resonators are important for quantum information storage and addressing. In this work we study the resonance frequency and loss in superconducting coplanar waveguide resonators as a function of temperature and power. We

Low loss superconducting titanium nitride coplanar waveguide resonators

December 9, 2010
Author(s)
Michael Vissers, Jiansong Gao, David S. Wisbey, David P. Pappas, C. C. Tsuei, A. D. Corcoles, Matthias Steffen
Thin films of TiN were sputter-deposited onto Si and sapphire wafers with and without SiN buffer layers. The films were fabricated into RF coplanar waveguide resonators, and internal quality factor measurements were taken at millikelvin temperatures in