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Search Publications by: Raymond Simmonds (Fed)

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Displaying 51 - 75 of 87

Arbitrary Control of Entanglement between Two Superconducting Resonators

July 27, 2010
Author(s)
Raymond W. Simmonds
We present a method to synthesize an arbitrary quantum state of two superconducting resonators. This state-synthesis algorithm utilizes a coherent interaction of each resonator with a tunable arti cial atom to create entangled quantum superpositions of

RFSQUID-Mediated Coherent Tunable Coupling Between a Superconducting Phase Qubit and a Lumped Element Resonator

April 29, 2010
Author(s)
Michael S. Allman, Fabio Altomare, Jed D. Whittaker, Katarina Cicak, Dale Li, Adam J. Sirois, Joshua Strong, John D. Teufel, Raymond W. Simmonds
We demonstrate coherent tunable coupling between a superconducting phase qubit and a lumpedelement resonator. The coupling strength is mediated by a flux-biased rf SQUID operated in the nonhysteretic regime. By tuning the applied flux bias to the rf SQUID

Low-loss superconducting resonant circuits using vacuum-gap -based microwave components

March 4, 2010
Author(s)
Katarina Cicak, Dale Li, Joshua Strong, Michael S. Allman, Fabio Altomare, Adam J. Sirois, Jed D. Whittaker, Raymond W. Simmonds
We have produced high quality resonant microwave circuits through developing a vacuum-gap technology for fabricating lumped-element capacitive and inductive components. We use micromachining to eliminate amorphous dielectric materials leaving vacuum in

Vacuum-Gap Capacitors for Low-Loss Superconducting Resonant Circuits

June 16, 2009
Author(s)
Katarina Cicak, Michael S. Allman, Joshua Strong, Kevin Osborn, Raymond W. Simmonds
Low-loss microwave components are used in many superconducting resonant circuits from multiplexed readouts of low-temperature detector arrays to quantum bits. Two-level system (TLS) defects in amorphous dielectric materials cause excess energy loss. In an

Electromagnetically induced transparency in a superconducting three-level system

April 16, 2009
Author(s)
Mika Sillanpaa, Katarina Cicak, Fabio Altomare, Jae Park, Raymond Simmonds, Jian Li, G. S. Paraoanu, Pertti Hakonen
When a three-level quantum system is irradiated by an intense coupling field resonant with two of the three possible transitions, the resonant absorption of the system from its ground state by an additional radiation field is suppressed. This effect, where

Coupled Macroscopic Quantum Resonators: Entanglement and Squeezed State

October 16, 2008
Author(s)
Lin Tian, Raymond Simmonds
Linear coupling between solid-state quantum resonators generates entanglement and squeezing effectively. We study the coupled system of a nanomechanical resonator and a superconducting electrical resonator as well as two electrical resonators coupled

Frequency-Tunable Josephson Junction Resonator for Quantum Computing

June 23, 2007
Author(s)
Kevin Osborn, Joshua Strong, Adam J. Sirois, Raymond W. Simmonds
We have fabricated and measured a high-Q Josephson junction resonator with a tunable resonance frequency. A dc magnetic flux allows the resonance frequency to be changed by over 10%. Weak coupling to the environment allows a quality factor of 7000 in the

Elimination of two level fluctuators in superconducting quantum bits by an epitaxial tunnel barrier

September 7, 2006
Author(s)
Seongshik Oh, Katarina Cicak, Jeffrey S. Kline, Mika Sillanpaa, Jed D. Whittaker, Raymond W. Simmonds, David P. Pappas, Kevin Osborn
Quantum computing based on Josephson junction technology is considered promising due to its scalable architecture. However, decoherence is a major obstacle. Here, we report evidence for improved Josephson quantum bits qubits using a single-crystal Al2O3

Josephson Junction Materials Research Using Phase Qubits

May 30, 2006
Author(s)
Raymond Simmonds, Dustin P. Hite, Robert McDermott, Matthias Steffen, Ken B. Cooper, Kristine Lang, John M. Martinis, David P. Pappas
At present, the performance of superconducting qubits is limited by decoherence. Strong decoherence of phase qubits is associated with spurious microwave resonators residing within the Josephson junction tunnel barrier [1]. In this work, we investigate

Decoherence in Josephson Qubits from Dielectric Loss

November 16, 2005
Author(s)
John M. Martinis, Ken B. Cooper, Robert Mcdermott, Matthias Steffen, Markus Ansmann, Kevin Osborn, Katarina Cicak, Seongshik Oh, David P. Pappas, Raymond Simmonds, Clare Yu
Dielectric loss from two-level states is shown to be a dominant decoherence source in superconducting quantum bits. Depending on the qubit design, dielectric loss from insulating materials or the tunnel junction can lead to short coherence times. We show

Epitaxial growth of rhenium with sputtering

October 6, 2005
Author(s)
Seongshik Oh, Dustin P. Hite, Katarina Cicak, Kevin Osborn, Raymond W. Simmonds, Robert Mcdermott, Ken B. Cooper, Matthias Steffen, John M. Martinis, David P. Pappas
We have grown epitaxial renium (0001) films on α-Al 2O 3(0001) substrates using sputter deposition in an ultra high vacuum system. We find that better epitaxy is achieved with DC rather than with RF sputtering. With DC sputtering, epitaxy is obtained with