1,987 research outputs found
Characterization of a multimode coplanar waveguide parametric amplifier
We characterize a novel Josephson parametric amplifier based on a
flux-tunable quarter-wavelength resonator. The fundamental resonance frequency
is ~1GHz, but we use higher modes of the resonator for our measurements. An
on-chip tuning line allows for magnetic flux pumping of the amplifier. We
investigate and compare degenerate parametric amplification, involving a single
mode, and nondegenerate parametric amplification, using a pair of modes. We
show that we reach quantum-limited noise performance in both cases, and we show
that the added noise can be less than 0.5 added photons in the case of low
gain
Single-shot Readout of a Superconducting Qubit using a Josephson Parametric Oscillator
We propose and demonstrate a new read-out technique for a superconducting
qubit by dispersively coupling it to a Josephson parametric oscillator. We
employ a tunable quarter-wavelength superconducting resonator and modulate its
resonant frequency at twice its value with an amplitude surpassing the
threshold for parametric instability. We map the qubit states onto two distinct
states of classical parametric oscillation: one oscillating state, with
photons in the resonator, and one with zero oscillation amplitude.
This high contrast obviates a following quantum-limited amplifier. We
demonstrate proof-of-principle, single-shot readout performance, and present an
error budget indicating that this method can surpass the fidelity threshold
required for quantum computing.Comment: 11 pages, 5 figure
Removal of filler material from large high energy formed parts
Filler material is removed by applying steam heat at 88.99 C to underside of workpiece and allowing filler to melt and drain from the waffle grids
Intrinsic magnetism in KTaO heterostructures
There has been intense recent interest in the two-dimensional electron gases
(2DEGs) that form at the surfaces and interfaces of KTaO (KTO), with the
discovery of superconductivity at temperatures significantly higher than those
of similar 2DEGs based on SrTiO (STO). Like STO heterostructures, these KTO
2DEGs are formed by depositing an overlayer on top of appropriately prepared
KTO surfaces. Some of these overlayers are magnetic, and the resulting 2DEGs
show signatures of this magnetism, including hysteresis in the
magnetoresistance (MR). Here we show that KTO 2DEGs fabricated by depositing
AlO on top of KTO also show hysteretic MR, indicative of long range
magnetic order, even though the samples nominally contain no intrinsic magnetic
elements. The hysteresis appears in both the transverse and longitudinal
resistance in magnetic fields both perpendicular to and in the plane of the
2DEG. The hysteretic MR has different characteristic fields and shapes for
surfaces of different crystal orientations, and vanishes above a few Kelvin.
Density functional theory (DFT) calculations indicate that the magnetism likely
arises from Ta local moments created in the presence of oxygen
vacancies.Comment: 5 pages, 4 figures, supplemental materials. arXiv admin note: text
overlap with arXiv:2209.1053
Concepts in Animal Parasitology, Chapter 67: Acari (Order): Mites
Chapter 67 in Concepts in Animal Parasitology on mites (order Acari) by David Evans Walter, Gerald W. Krantz, and Evert E. Lindquist. 2024. S. L. Gardner and S. A. Gardner, editors. Zea Books, Lincoln, Nebraska, United States. doi: 10.32873/unl.dc.ciap06
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