285 research outputs found
Linear circuit models for on-chip quantum electrodynamics
We present equivalent circuits that model the interaction of microwave
resonators and quantum systems. The circuit models are derived from a general
interaction Hamiltonian. Quantitative agreement between the simulated resonator
transmission frequency, qubit Lamb shift and experimental data will be shown.
We demonstrate that simple circuit models, using only linear passive elements,
can be very useful in understanding systems where a small quantum system is
coupled to a classical microwave apparatus
Comparative analysis of resonant phonon THz quantum cascade lasers
We present a comparative analysis of a set of GaAs-based THz quantum cascade
lasers, based on longitudinal-optical phonon scattering depopulation, by using
an ensemble Monte Carlo simulation, including both carrier-carrier and
carrier-phonon scattering. The simulation shows that the parasitic injection
into the states below the upper laser level limits the injection efficiency and
thus the device performance at the lasing threshold. Additional detrimental
effects playing an important role are identified. The simulation results are in
reasonable agreement with the experimental findings.Comment: 3 pages, 3 figure
Fermionic state discrimination by local operations and classical communication
We consider the problem of local operations and classical communication
(LOCC) discrimination between two bipartite pure states of fermionic systems.
We show that, contrary to the case of quantum systems, for fermionic systems it
is generally not possible to achieve the ideal state discrimination
performances through LOCC measurements. On the other hand, we show that an
ancillary system made of two fermionic modes in a maximally entangled state is
a sufficient additional resource to attain the ideal performances via LOCC
measurements. The stability of the ideal results is studied when the
probability of preparation of the two states is perturbed, and a tight bound on
the discrimination error is derived.Comment: 8 pages, 1 figur
Modeling bound-to-continuum terahertz quantum cascade lasers: The role of Coulomb interactions
Based on an ensemble Monte Carlo analysis, we show that Coulomb interactions
play a dominant role in bound-to-continuum terahertz quantum cascade lasers and
thus require careful modeling. Coulomb interactions enter our simulation in the
form of space charge effects as well as Coulomb scattering events. By
comparison to a full many-subband Coulomb screening model, we show that
simplified approaches produce considerable deviations for such structures. Also
the spin dependence of electron-electron scattering has to be adequately
considered. Moreover, we demonstrate that iterative Schr\"{o}dinger-Poisson and
carrier transport simulations are necessary to correctly account for space
charge effects
Shear-Force Sensors on Flexible Substrates Using Inkjet Printing
Printing techniques are a promising way of fabricating low-cost electronics without the need for masking and etching. In recent years, additive printing techniques, such as inkjet and screen printing, have been adopted to fabricate low-cost and large-area electronics on flexible substrates. In this work, a three-axial normal and shear force sensor was designed and printed that consists of four miniaturized, printed capacitors. The partially overlapping electrodes are arranged in a manner, so that force sensitivity in orthogonal directions is achieved. A silicone rubber is used as an elastic dielectric and spacer between the two electrodes. The base unit of this sensor has been fabricated using inkjet printing and characterized for normal and shear forces. The force response was investigated in a force range from 0.1 N to 8 N, the normal-force sensitivity was determined to be Sz=5.2 fF/N, and the shear-force sensitivity was Sy=13.1 fF/N. Due to its sensing range, this sensor could be applicable in tactile sensing systems like wearables and artificial electronic skins
Draft Genome Sequence of the Carboxydotrophic Alphaproteobacterium Aminobacter carboxidus Type Strain DSM 1086
Aminobacter carboxidus is a soil Gram-negative alphaproteobacterium belonging to the physiological group of carboxydobacteria which aerobically oxidize CO to CO2 Here, we report the draft genome sequence of the A. carboxidus DSM 1086 type strain and the identification of both form I and form II CO dehydrogenase systems in this strain
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