3,946 research outputs found
Surface Acoustic Solitons - Quantum Theoretical Approach
Zadanie pt. Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki nr 885/P-DUN/2014 zostało dofinansowane ze środków MNiSW w ramach działalności upowszechniającej naukę
Evaluation of a gate capacitance in the sub-aF range for a chemical field-effect transistor with a silicon nanowire channel
An evaluation of the gate capacitance of a field-effect transitor (FET) whose
channel length and width are several ten nanometer, is a key point for sensors
applications. However, experimental and precise evaluation of capacitance in
the aF range or less has been extremely difficult. Here, we report an
extraction of the capacitance down to 0.55 aF for a silicon FET with a
nanoscale wire channel whose width and length are 15 and 50 nm, respectively.
The extraction can be achieved by using a combination of four kinds of
measurements: current characteristics modulated by double gates,
random-telegraph-signal noise induced by trapping and detrapping of a single
electron, dielectric polarization noise, and current characteristics showing
Coulomb blockade at low temperature. The extraction of such a small gate
capacitance enables us to evaluate electron mobility in a nanoscale wire using
a classical model of current characteristics of a FET.Comment: To be published in IEEE Trans. Nanotechno
Capital allocation and bank management based on the quantification of credit risk
This paper was presented at the conference "Financial services at the crossroads: capital regulation in the twenty-first century" as part of session 2, "Credit risk modeling." The conference, held at the Federal Reserve Bank of New York on February 26-27, 1998, was designed to encourage a consensus between the public and private sectors on an agenda for capital regulation in the new century.Bank capital ; Bank loans ; Risk ; Bank management
Long-range nematic order and anomalous fluctuations in suspensions of swimming filamentous bacteria
We study the collective dynamics of elongated swimmers in a very thin fluid
layer by devising long, filamentous, non-tumbling bacteria. The strong
confinement induces weak nematic alignment upon collision, which, for large
enough density of cells, gives rise to global nematic order. This homogeneous
but fluctuating phase, observed on the largest experimentally-accessible scale
of millimeters, exhibits the properties predicted by standard models for
flocking such as the Vicsek-style model of polar particles with nematic
alignment: true long-range nematic order and non-trivial giant number
fluctuations.Comment: 6 pages, 4 figures. Supplemental Material: 6 pages, 3 figure
One-by-one trap activation in silicon nanowire transistors
Flicker or 1/f noise in metal-oxide-semiconductor field-effect transistors
(MOSFETs) has been identified as the main source of noise at low frequency. It
often originates from an ensemble of a huge number of charges trapping and
detrapping. However, a deviation from the well-known model of 1/f noise is
observed for nanoscale MOSFETs and a new model is required. Here, we report the
observation of one-by-one trap activation controlled by the gate voltage in a
nanowire MOSFET and we propose a new low-frequency-noise theory for nanoscale
FETs. We demonstrate that the Coulomb repulsion between electronically charged
trap sites avoids the activation of several traps simultaneously. This effect
induces a noise reduction by more than one order of magnitude. It decreases
when increasing the electron density in the channel due to the electrical
screening of traps. These findings are technologically useful for any FETs with
a short and narrow channel.Comment: One file with paper and supplementary informatio
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