4,167 research outputs found
Efficient orthogonal control of tunnel couplings in a quantum dot array
Electrostatically-defined semiconductor quantum dot arrays offer a promising
platform for quantum computation and quantum simulation. However, crosstalk of
gate voltages to dot potentials and inter-dot tunnel couplings complicates the
tuning of the device parameters. To date, crosstalk to the dot potentials is
routinely and efficiently compensated using so-called virtual gates, which are
specific linear combinations of physical gate voltages. However, due to
exponential dependence of tunnel couplings on gate voltages, crosstalk to the
tunnel barriers is currently compensated through a slow iterative process. In
this work, we show that the crosstalk on tunnel barriers can be efficiently
characterized and compensated for, using the fact that the same exponential
dependence applies to all gates. We demonstrate efficient calibration of
crosstalk in a quadruple quantum dot array and define a set of virtual barrier
gates, with which we show orthogonal control of all inter-dot tunnel couplings.
Our method marks a key step forward in the scalability of the tuning process of
large-scale quantum dot arrays.Comment: 8 pages, 7 figure
Jetted mixtures of particle suspensions and resins
This is the author accepted manuscript. The final version is available from AIP at http://scitation.aip.org/content/aip/journal/pof2/26/10/10.1063/1.4897238.Drop-on-demand (DoD) ink-jetting of hard particle suspensions with volume fraction Ī¦ ~ 0.25 has been surveyed using 1000 ultra-high speed videos as a function of particle size (d90 = 0.8-3.6 Āµm), with added 2 wt% acrylic (250 kDa) or 0.5 wt% cellulose (370 kDa) resin, and also compared with Newtonian analogues. Jet break-off times from 80 Āµm diameter nozzles were insensitive (120Ā±10 Āµs) to particle size, and resin jet break-off times were not significantly altered by > 30 wt% added particles. Different particle size grades can be jetted equally well in practice, while resin content effectively controls DoD break-off times
A population-based temporal logic gate for timing and recording chemical events
Engineered bacterial sensors have potential applications in human health monitoring, environmental chemical detection, and materials biosynthesis. While such bacterial devices have long been engineered to differentiate between combinations of inputs, their potential to process signal timing and duration has been overlooked. In this work, we present a twoāinput temporal logic gate that can sense and record the order of the inputs, the timing between inputs, and the duration of input pulses. Our temporal logic gate design relies on unidirectional DNA recombination mediated by bacteriophage integrases to detect and encode sequences of input events. For an E. coli strain engineered to contain our temporal logic gate, we compare predictions of Markov model simulations with laboratory measurements of final population distributions for both step and pulse inputs. Although single cells were engineered to have digital outputs, stochastic noise created heterogeneous singleācell responses that translated into analog population responses. Furthermore, when singleācell genetic states were aggregated into populationālevel distributions, these distributions contained unique information not encoded in individual cells. Thus, final differentiated subāpopulations could be used to deduce order, timing, and duration of transient chemical events
Direct CP and T Violation in Baryonic B Decays
We review the direct CP and T violation in the three-body baryonic B decays
in the standard model. In particular, we emphasize that the direct CP violating
asymmetry in is around 22% and the direct
violating asymmetry in \bar B^0 \ra \Lambda \bar p \pi^+ can be as large as
12%, which are accessible to the current B factories at KEK and SLAC as well as
SuperB and LHCb.Comment: 6 pages, Talk given at 4th International Conference on Flavor Physics
(ICFP 2007), Beijing, China, 24-28 Sep 200
Lower bounds on photometric redshift errors from Type Ia supernovae templates
Cosmology with Type Ia supernovae heretofore has required extensive
spectroscopic follow-up to establish a redshift. Though tolerable at the
present discovery rate, the next generation of ground-based all-sky survey
instruments will render this approach unsustainable. Photometry-based redshift
determination is a viable alternative, but introduces non-negligible errors
that ultimately degrade the ability to discriminate between competing
cosmologies. We present a strictly template-based photometric redshift
estimator and compute redshift reconstruction errors in the presence of
photometry and statistical errors. With reasonable assumptions for a cadence
and supernovae distribution, these redshift errors are combined with systematic
errors and propagated using the Fisher matrix formalism to derive lower bounds
on the joint errors in and relevant to the next
generation of ground-based all-sky survey.Comment: 23 pages, 6 figure
Internal fracture caused by focusing of explosive waves
Internal fracture caused by focusing of explosive wave
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