9,126 research outputs found
Magnon dark modes and gradient memory
Extensive efforts have been expended in developing hybrid quantum systems to
overcome the short coherence time of superconducting circuits by introducing
the naturally long-lived spin degree of freedom. Among all the possible
materials, single-crystal yttrium iron garnet has shown up very recently as a
promising candidate for hybrid systems, and various highly coherent
interactions, including strong and even ultra-strong coupling, have been
demonstrated. One distinct advantage of these systems is that the spins are in
the form of well-defined magnon modes, which allows flexible and precise
tuning. Here we demonstrate that by dissipation engineering, a non-Markovian
interaction dynamics between the magnon and the microwave cavity photon can be
achieved. Such a process enables us to build a magnon gradient memory to store
information in the magnon dark modes, which decouple from the microwave cavity
and thus preserve a long life-time. Our findings provide a promising approach
for developing long-lifetime, multimode quantum memories.Comment: 18 pages, 12 figure
Design and test results of different aluminum coating layers on the sCMOS sensors for soft X-ray detection
In recent years, tremendous progress has been made on complementary
metal-oxide-semiconductor (CMOS) sensors for applications as X-ray detectors.
To shield the visible light in X-ray detection, a blocking filter of aluminum
is commonly employed. We designed three types of aluminum coating layers, which
are deposited directly on the surface of back-illuminated sCMOS sensors during
fabrication. A commercial 2k * 2k sCMOS sensor is used to realize these
designs. In this work, we report their performance by comparison with that of
an uncoated sCMOS sensor. The optical transmissions at 660 nm and 850 nm are
measured, and the results show that the optical transmission reaches a level of
about 10-9 for the 200 nm aluminum layer and about 10-4 for the 100 nm aluminum
layer. Light leakage is found around the four sides of the sensor. The readout
noise, fixed-pattern noise and energy resolution of these Al-coated sCMOS
sensors do not show significant changes. The dark currents of these Al-coated
sCMOS sensors show a noticeable increase compared with that of the uncoated
sCMOS sensor at room temperatures, while no significant difference is found
when the sCMOS sensors are cooled down to about -15 degree. The aluminum
coatings show no visible crack after the thermal cycle and aging tests. Based
on these results, an aluminum coating of a larger area on larger sCMOS sensors
is proposed for future work.Comment: Accept for publication in JIns
Relaxed stability conditions based on Taylor series membership functions for polynomial fuzzy-model-based control systems
© 2014 IEEE. In this paper, we investigate the stability of polynomial fuzzy-model-based (PFMB) control systems, aiming to relax stability conditions by considering the information of membership functions. To facilitate the stability analysis, we propose a general form of approximated membership functions, which is implemented by Taylor series expansion. Taylor series membership functions (TSMF) can be brought into stability conditions such that the relation between membership grades and system states is expressed. To further reduce the con-servativeness, different types of information are taken into account: the boundary of membership functions, the property of membership functions, and the boundary of operating domain. Stability conditions are obtained from Lyapunov stability theory by sum of squares (SOS) approach. Simulation examples demonstrate the effect of each piece of information
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