20,315 research outputs found
Complex Scalar DM in a B-L Model
In this work, we implement a complex scalar Dark Matter (DM) candidate in a
gauge extension of the Standard Model. The model contains three
right handed neutrinos with different quantum numbers and a rich scalar sector,
with extra doublets and singlets. In principle, these extra scalars can have
VEVs ( and for the extra doublets and singlets,
respectively) belonging to different energy scales. In the context of
, which allows to obtain naturally
light active neutrino masses and mixing compatible with neutrino experiments,
the DM candidate arises by imposing a symmetry on a given complex
singlet, , in order to make it stable. After doing a study of the
scalar potential and the gauge sector, we obtain all the DM dominant processes
concerning the relic abundance and direct detection. Then, for a representative
set of parameters, we found that a complex DM with mass around GeV, for
example, is compatible with the current experimental constraints without
resorting to resonances. However, additional compatible solutions with heavier
masses can be found in vicinities of resonances. Finally, we address the issue
of having a light CP-odd scalar in the model showing that it is safe concerning
the Higgs and the boson invisible decay widths, and also the energy
loss in stars astrophysical constraints.Comment: 20 pages, 3 figure
The Impact of Deuterated CMOS processing on Gate Oxide Reliability
In recent literature, a controversy has arisen over the question whether deuterium improves the stability of the MOS gate dielectric. In particular, the influence of deuterium incorporation on the bulk oxide quality is not clear. In this letter, deuterium or hydrogen is introduced during either the gate oxidation, postoxidation anneal, and/or the postmetal anneal (PMA). The oxide bulk degradation was evaluated using charge-to-breakdown and stress-induced leakage current; and the oxide interface degradation using hot-carrier degradation and low-frequency noise. The obtained results show that the oxide bulk does not benefit from the presence of deuterium, regardless of the stage of deuterium introduction, or the gate oxide thickness. The oxide interface is more stable only when deuterium is introduced in the PMA
Phase Separation in Charge-Stabilized Colloidal Suspensions: Influence of Nonlinear Screening
The phase behavior of charge-stabilized colloidal suspensions is modeled by a
combination of response theory for electrostatic interparticle interactions and
variational theory for free energies. Integrating out degrees of freedom of the
microions (counterions, salt ions), the macroion-microion mixture is mapped
onto a one-component system governed by effective macroion interactions. Linear
response of microions to the electrostatic potential of the macroions results
in a screened-Coulomb (Yukawa) effective pair potential and a one-body volume
energy, while nonlinear response modifies the effective interactions [A. R.
Denton, \PR E {\bf 70}, 031404 (2004)]. The volume energy and effective pair
potential are taken as input to a variational free energy, based on
thermodynamic perturbation theory. For both linear and first-order nonlinear
effective interactions, a coexistence analysis applied to aqueous suspensions
of highly charged macroions and monovalent microions yields bulk separation of
macroion-rich and macroion-poor phases below a critical salt concentration, in
qualitative agreement with predictions of related linearized theories [R. van
Roij, M. Dijkstra, and J.-P. Hansen, \PR E {\bf 59}, 2010 (1999); P. B. Warren,
\JCP {\bf 112}, 4683 (2000)]. It is concluded that nonlinear screening can
modify phase behavior but does not necessarily suppress bulk phase separation
of deionized suspensions.Comment: 14 pages of text + 9 figure
Modeling of RTS noise in MOSFETs under steady-state and large-signal excitation
The behavior of RTS noise in MOSFETs under large-signal excitation is experimentally studied. Our measurements show a significant transient effect, in line with earlier reports. We present a new physical model to describe this transient behavior and to predict RTS noise in MOSFETs under large-signal excitation. With only three model parameters the behavior is well described, contrary to existing models
Recommended from our members
Improving nanopore read accuracy with the R2C2 method enables the sequencing of highly multiplexed full-length single-cell cDNA.
High-throughput short-read sequencing has revolutionized how transcriptomes are quantified and annotated. However, while Illumina short-read sequencers can be used to analyze entire transcriptomes down to the level of individual splicing events with great accuracy, they fall short of analyzing how these individual events are combined into complete RNA transcript isoforms. Because of this shortfall, long-distance information is required to complement short-read sequencing to analyze transcriptomes on the level of full-length RNA transcript isoforms. While long-read sequencing technology can provide this long-distance information, there are issues with both Pacific Biosciences (PacBio) and Oxford Nanopore Technologies (ONT) long-read sequencing technologies that prevent their widespread adoption. Briefly, PacBio sequencers produce low numbers of reads with high accuracy, while ONT sequencers produce higher numbers of reads with lower accuracy. Here, we introduce and validate a long-read ONT-based sequencing method. At the same cost, our Rolling Circle Amplification to Concatemeric Consensus (R2C2) method generates more accurate reads of full-length RNA transcript isoforms than any other available long-read sequencing method. These reads can then be used to generate isoform-level transcriptomes for both genome annotation and differential expression analysis in bulk or single-cell samples
Self-normalizing phase measurement in multimode terahertz spectroscopy based on photomixing of three lasers
Photomixing of two near-infrared lasers is well established for
continuous-wave terahertz spectroscopy. Photomixing of three lasers allows us
to measure at three terahertz frequencies simultaneously. Similar to Fourier
spectroscopy, the spectral information is contained in an nterferogram, which
is equivalent to the waveform in time-domain spectroscopy. We use one fixed
terahertz frequency \nu_ref to monitor temporal drifts of the setup, i.e., of
the optical path-length difference. The other two frequencies are scanned for
broadband high-resolution spectroscopy. The frequency dependence of the phase
is obtained with high accuracy by normalizing it to the data obtained at
\nu_ref, which eliminates drifts of the optical path-length difference. We
achieve an accuracy of about 1-2 microns or 10^{-8} of the optical path length.
This method is particularly suitable for applications in nonideal environmental
conditions outside of an air-conditioned laboratory.Comment: 5 pages, 5 figure
Nonlinear Screening and Effective Electrostatic Interactions in Charge-Stabilized Colloidal Suspensions
A nonlinear response theory is developed and applied to electrostatic
interactions between spherical macroions, screened by surrounding microions, in
charge-stabilized colloidal suspensions. The theory describes leading-order
nonlinear response of the microions (counterions, salt ions) to the
electrostatic potential of the macroions and predicts microion-induced
effective many-body interactions between macroions. A linear response
approximation [Phys. Rev. E 62, 3855 (2000)] yields an effective pair potential
of screened-Coulomb (Yukawa) form, as well as a one-body volume energy, which
contributes to the free energy. Nonlinear response generates effective
many-body interactions and essential corrections to both the effective pair
potential and the volume energy. By adopting a random-phase approximation (RPA)
for the response functions, and thus neglecting microion correlations,
practical expressions are derived for the effective pair and triplet potentials
and for the volume energy. Nonlinear screening is found to weaken repulsive
pair interactions, induce attractive triplet interactions, and modify the
volume energy. Numerical results for monovalent microions are in good agreement
with available ab initio simulation data and demonstrate that nonlinear effects
grow with increasing macroion charge and concentration and with decreasing salt
concentration. In the dilute limit of zero macroion concentration,
leading-order nonlinear corrections vanish. Finally, it is shown that nonlinear
response theory, when combined with the RPA, is formally equivalent to the
mean-field Poisson-Boltzmann theory and that the linear response approximation
corresponds, within integral-equation theory, to a linearized hypernetted-chain
closure.Comment: 30 pages, 8 figures, Phys. Rev. E (in press
Power processing unit for hall-effect thrusters on "Meteor-M №3 spacecraf"
The development results of power processing unit (PPU-M) for hall-effect thrusters on "Meteor-M №3" spacecraft are considered. The structure, weight, dimensions and main technical characteristics of the system in the paper are presented. The work peculiarity of the system is unstable input voltage of both power bus and control bus that increases the ripple voltages and currents at the input and the output and causes the additional requirements to the circuit design. A comparative analysis of the system characteristics and European analogs was carried out, and then a conclusion on the basis of available data that the characteristics of the system are not inferior to European analogs was mad
- …