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: Joe Aumentado (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 26 - 50 of 75

Two-port microwave calibration at millikelvin temperatures

March 15, 2013
Author(s)
Leonardo M. Ranzani, Jose A. Aumentado, Lafe F. Spietz, Zoya Popovic
In this work we introduce a system for 2-port microwave calibration at millikelvin temperatures operating at the coldest stage of a dilution refrigerator by use of an adapted thru-reflect-line algorithm. We show that this can be an effective tool for

Two-port microwave calibration at milliKelvin temperatures

March 5, 2013
Author(s)
Leonardo M. Ranzani, Lafe F. Spietz, Zoya Popovic, Jose A. Aumentado
In this work we introduce a system for 2-port microwave calibration at millikelvin temperatures operating at the coldest stage of a dilution refrigerator by use of an adapted thru-reflect-line algorithm. We show that this can be an effective tool for

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

A 4:1 transmission-line impedance transformer for broadband superconducting circuits

October 1, 2012
Author(s)
Leonardo M. Ranzani, Lafe F. Spietz, Jose A. Aumentado, Zoya Popovic
We present a 4 : 1 superconducting transmission-line impedance transformer for cryogenic applications. The device transforms 25 {Ω} in the coplanar waveguide to 6.25 {Ω} in the microstrip and is designed to operate at 20 mK. Calibrated measurements in a

Quantum interference between two single photons of different microwave frequencies

April 20, 2012
Author(s)
Francois E. Nguyen, Eva A. Zakka-Bajjani, Jose A. Aumentado, Raymond W. Simmonds
Quantum interference is an important tool for fields such as lithography, metrology and quantum processing. Two identical optical photons (photons with the same wavelength and polarization) simultaneously sent through the two input ports of a semi

Quantum superposition of a single microwave photon in two different colour states

July 3, 2011
Author(s)
Eva A. Zakka-Bajjani, Francois E. Nguyen, Minhyea Lee, Leila R. Vale, Raymond Simmonds, Joe Aumentado
The ability to manipulate photonic states is an important tool for quantum information processing. In cavity quantum electrodynamics (QED), coupling between bosonic modes has, until now, required a qubit to mediate the interaction. As an alternative, it is

The Cooper Pair Transistor

September 17, 2010
Author(s)
Jose A. Aumentado
The Cooper pair transistor (CPT) is a superconducting electrometer that has applications in quantum information as well as fundamental superconductivity studies. Since it operates in a near-dissipationless mode, it has potential as a minimally invasive

Energy Decay in Josephson Qubits from Non-equilibrium Quasiparticles

August 26, 2009
Author(s)
Jose A. Aumentado, John M. Martinis, M Ansmann
We calculate the energy decay rate of Josephson qubits and superconducting resonators from non-equilibrium quasiparticles. The decay rates from experiments are shown to be consistent with our predictions based on a prior measurement of the quasiparticle

Phase Locking Transition in a Chirped Superconducting Josephson Resonator

September 12, 2008
Author(s)
Jose A. Aumentado, Ofer Naaman, L Friedland, J.S. Wurtele, Irfan Siddiqi
We observe a sharp threshold for autoresonant phase locking in a transmission line resonator embedded with a Josephson tunnel junction and driven with a purely ac, chirped microwave signal. When the drive amplitude is below a critical value, the resonator

Narrow band microwave radiation from a biased single-Cooper-pair transistor

May 29, 2007
Author(s)
Ofer Naaman, Joe Aumentado
We show that a single-Cooper-pair transistor (SCPT) electrometer emits narrow-band microwave radiation when biased in its sub-gap region. Photo-activation of quasiparticle tunneling in a nearby SCPT is used to spectroscopically detect this radiation, in a