8,364 research outputs found
Frequency-Tunable Josephson Junction Resonator for Quantum Computing
We have fabricated and measured a high-Q Josephson junction resonator with a
tunable resonance frequency. A dc magnetic flux allows the resonance frequency
to be changed by over 10 %. Weak coupling to the environment allows a quality
factor of 7000 when on average less than one photon is stored in the
resonator. At large photon numbers, the nonlinearity of the Josephson junction
creates two stable oscillation states. This resonator can be used as a tool for
investigating the quality of Josephson junctions in qubits below the single
photon limit, and can be used as a microwave qubit readout at high photon
numbers.Comment: 3 pages, 5 figure
An experimental investigation of the hypergolic ignition of some polymeric fuels with oxygen
Hypergolic ignition of polymeric fuels with oxyge
Adaptive Multigrid Algorithm for Lattice QCD
We present a new multigrid solver that is suitable for the Dirac operator in
the presence of disordered gauge fields. The key behind the success of the
algorithm is an adaptive projection onto the coarse grids that preserves the
near null space. The resulting algorithm has weak dependence on the gauge
coupling and exhibits very little critical slowing down in the chiral limit.
Results are presented for the Wilson Dirac operator of the 2d U(1) Schwinger
model.Comment: 4 pages, 2 figure
Ground-layer adaptive-optics system modelling for the ChineseLarge Optical/Infrared Telescope
The Chinese Large Optical/Infrared Telescope is currently undergoing design studies. A ground-layer adaptive-optics system (GLAO) has been proposed, with a 14 -arcmin field of view (FOV) and moderate adaptive-optics correction using a deformable secondary mirror, several laser guide stars (LGS) and wavefront sensors. Due to its large FOV and relatively complex structure, some important problems should be analysed to aid budget considerations for the whole telescope. In this paper, we propose a FOV-related evaluation factor to describe the GLAO performance and use an end-to-end Monte Carlo simulation to test its performance under different configurations. To accelerate the parameter space exploration speed, we split the parameter space of the GLAO system and apply a bottom-up search procedure for parameter selection. We also propose a simplified turbulence geometric model to evaluate the GLAO performance with different turbulence-profile-related parameters. With the above methods, we analyse the required number of deformable mirror (DM) actuators, the number, position and magnitude of LGS and explore the DM tilt-conjugation problem for this GLAO system
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