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Related papers: Noise scaling in SQUID arrays

200 papers

Using a point (superconductor-constriction-superconductor, ScS) contact in a single-Josephson-junction superconducting quantum interference device (RF SQUID) provides stochastic resonance conditions at any arbitrary small value of loop…

Superconductivity · Physics 2014-02-06 O. G. Turutanov , V. A. Golovanevskiy , V. Yu. Lyakhno , V. I. Shnyrkov

The noise in stochastic gradient descent (SGD), caused by minibatch sampling, is poorly understood despite its practical importance in deep learning. This work presents the first systematic study of the SGD noise and fluctuations close to a…

Machine Learning · Computer Science 2022-03-09 Liu Ziyin , Kangqiao Liu , Takashi Mori , Masahito Ueda

A theoretical study on the voltage response function <V> of a series array of dc SQUIDs is presented in which the elementary dc SQUID loops vary in size and, possibly, in orientation. Such series arrays of two-junction SQUIDs possess…

Superconductivity · Physics 2009-10-31 Ch. Haeussler , J. Oppenlaender , N. Schopohl

Correlated noise across multi-qubit architectures is known to be highly detrimental to the operation of error correcting codes and the long-term feasibility of quantum processors. The recent discovery of spatially dependent correlated noise…

We have used a dc Superconducting QUantum Interference Device to measure the magnetic flux noise generated by the equilibrium vortex density fluctuations associated with the Kosterlitz-Thouless-Berezinskii (KTB) transition in an overdamped…

Condensed Matter · Physics 2009-10-28 T. J. Shaw , M. J. Ferrari , D. -H. Lee , John Clarke , L. L. Sohn , M. Tinkham

We observe the suppression of the finite frequency shot-noise produced by a voltage biased tunnel junction due to its interaction with a single electromagnetic mode of high impedance. The tunnel junction is embedded in a quarter wavelength…

Mesoscale and Nanoscale Physics · Physics 2014-10-24 C. Altimiras , O. Parlavecchio , P. Joyez , D. Vion , P. Roche , D. Esteve , F. Portier

We study scaling laws of signSGD under a power-law random features (PLRF) model that accounts for both feature and target decay. We analyze the population risk of a linear model trained with one-pass signSGD on Gaussian-sketched features.…

Machine Learning · Computer Science 2026-03-03 Jihwan Kim , Dogyoon Song , Chulhee Yun

We study, by means of three-dimensional Monte Carlo simulations, the current-voltage (IV) characteristics and the voltage noise spectrum at low temperatures of driven magnetic flux lines interacting with randomly placed point or columnar…

Statistical Mechanics · Physics 2009-11-07 Jayajit Das , Thomas J. Bullard , Uwe C. Tauber

The requirements for the construction of ultra-sensitive SQUID instrumentation as used in biomagnetism are presented. Typically, SQUIDs are inductively coupled to pick-up coils and for this arrangement one can improve the noise performance…

Instrumentation and Detectors · Physics 2019-03-25 Rainer Körber

Using a simple lumped-circuit model, we numerically study the dependence of the voltage gain and noise on the amplifier's parameters. Linear, quasi-linear, and nonlinear regimes are studied. We have shown that the voltage gain of the…

Superconductivity · Physics 2015-05-30 G. P. Berman , O. O. Chumak , D. I. Kamenev , D. Kinion , V. I. Tsifrinovich

We report on the development of nearly quantum limited SQUIDs with miniature pickup loop dimensions. The implemented high quality and low capacitance cross-type Nb/AlOx/Nb Josephson junctions offer large $I_CR_N$-products and therefore…

Superconductivity · Physics 2017-05-18 M. Schmelz , V. Zakosarenko , T. Schönau , S. Anders , S. Linzen , R. Stolz , H. -G. Meyer

We derive general equations for non-linearity corrections and statistical uncertainty (variance) estimates for data acquired with near-infrared detectors employing correlated double sampling, multiple correlated double sampling (Fowler…

Astrophysics · Physics 2009-11-10 W. D. Vacca , M. C. Cushing , J. T. Rayner

Encoding information about continuous variables using noisy computational units is a challenge; nonetheless, asymptotic theory shows that combining multiple periodic scales for coding can be highly precise despite the corrupting influence…

Neurons and Cognition · Quantitative Biology 2013-08-22 Alexander Mathis , Andreas V. M. Herz , Martin B. Stemmler

We have studied the $1/f$ voltage noise of gold nano-contacts in electromigrated and mechanically controlled break-junctions having resistance values $R$ that can be tuned from 10 $\Omega$ (many channels) to 10 k$\Omega$ (single atom…

Mesoscale and Nanoscale Physics · Physics 2014-01-03 ZhengMing Wu , SongMei Wu , S. Oberholzer , M. Steinacher , M. Calame , C. Schönenberger

We describe a field-theoretic approach to calculate quantum shot noise in nanoscale conductors from first principles. Our starting point is the second-quantization field operator to calculate shot noise in terms of single quasi-particle…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Yu-Chang Chen , Massimiliano Di Ventra

We study the flux noise $S_{\Phi}(\omega)$ and finite frequency conductivity $\sigma_1(\omega)$ in two dimensional unfrustrated Josephson junction arrays (JJA's), by numerically solving the equations of the coupled overdamped…

Superconductivity · Physics 2009-10-30 Ing-Jye Hwang , Seungoh Ryu , D. Stroud

We have investigated asymmetrically shunted Nb/Al-AlO$_x$/Nb direct current (dc) superconducting quantum interference devices (SQUIDs). While keeping the total resistance $R$ identical to a comparable symmetric SQUID with $R^{-1} = R_1^{-1}…

Superconductivity · Physics 2015-06-05 M. Rudolph , J. Nagel , J. M. Meckbach , M. Kemmler , M. Siegel , K. Ilin , D. Koelle , R. Kleiner

We study the vector and scalar meson-meson amplitudes up to \sqrt{s}\lesssim 1.4 GeV and their associated spectroscopy. The study has been done considering jointly the N/D method, Chiral Symmetry and implications from large N_c QCD. The N/D…

High Energy Physics - Phenomenology · Physics 2009-10-31 J. A. Oller , E. Oset

We report on room temperature low frequency noise due to magnetic inhomogeneities/domain walls (MI/DWs) in elliptic submicron FeCoB/MgO/FeCoB magnetic tunnel junctions with an area between 0.0245 and 0.0675{\mu}m2. In the smaller area…

Mesoscale and Nanoscale Physics · Physics 2012-04-18 D. Herranz , A. Gomez-Ibarlucea , M. Schäfers , A. Lara , G. Reiss , F. G. Aliev

We report that low frequency (up to 200 kHz) noise spectra of magnetic tunnel junctions with areas ~10^{-10}cm^2$ at 10 Kelvin deviate significantly from the typical 1/f behavior found in large area junctions at room temperature. In most…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 B. Zhong , Y. Chen , S. Garzon , T. M. Crawford , R. A. Webb