788 research outputs found
Time-division SQUID multiplexers with reduced sensitivity to external magnetic fields
Time-division SQUID multiplexers are used in many applications that require
exquisite control of systematic error. One potential source of systematic error
is the pickup of external magnetic fields in the multiplexer. We present
measurements of the field sensitivity figure of merit, effective area, for both
the first stage and second stage SQUID amplifiers in three NIST SQUID
multiplexer designs. These designs include a new variety with improved
gradiometry that significantly reduces the effective area of both the first and
second stage SQUID amplifiers.Comment: 4 pages, 7 figures. Submitted for publication in the IEEE
Transactions on Applied Superconductivity, August 201
The development of the steel industry enhanced by the flows of foreign direct investment (FDI)
Despite the international economic crisis, the European Union has managed to maintain its important position in the world exports of metalwork manufactures, with slight imbalances recorded on its markets in 2010 and under circumstances of little importance for western European economies that have been actively competing with the Chinese economy. The metalworking industry is an important engine for the European economy, since it accounts for 10 % of the total added value of the manufacturing industries which amount to 7,5 % of its output volume. The present paper focuses on the role and the contribution of foreign direct investments (FDI) to the development and growth of this particular sector in the domestic economies of the EU
Strongly quadrature-dependent noise in superconducting micro-resonators measured at the vacuum-noise limit
We measure frequency- and dissipation-quadrature noise in superconducting
lithographed microwave resonators with sensitivity near the vacuum noise level
using a Josephson parametric amplifier. At an excitation power of 100~nW, these
resonators show significant frequency noise caused by two-level systems. No
excess dissipation-quadrature noise (above the vacuum noise) is observed to our
measurement sensitivity. These measurements demonstrate that the excess
dissipation-quadrature noise is negligible compared to vacuum fluctuations, at
typical readout powers used in micro-resonator applications. Our results have
important implications for resonant readout of various devices such as
detectors, qubits and nano-mechanical oscillators.Comment: 13 pages, 4 figure
- …