5,124 research outputs found
Using ultra-thin parylene films as an organic gate insulator in nanowire field-effect transistors
We report the development of nanowire field-effect transistors featuring an
ultra-thin parylene film as a polymer gate insulator. The room temperature,
gas-phase deposition of parylene is an attractive alternative to oxide
insulators prepared at high temperatures using atomic layer deposition. We
discuss our custom-built parylene deposition system, which is designed for
reliable and controlled deposition of <100 nm thick parylene films on III-V
nanowires standing vertically on a growth substrate or horizontally on a device
substrate. The former case gives conformally-coated nanowires, which we used to
produce functional -gate and gate-all-around structures. These give
sub-threshold swings as low as 140 mV/dec and on/off ratios exceeding at
room temperature. For the gate-all-around structure, we developed a novel
fabrication strategy that overcomes some of the limitations with previous
lateral wrap-gate nanowire transistors. Finally, we show that parylene can be
deposited over chemically-treated nanowire surfaces; a feature generally not
possible with oxides produced by atomic layer deposition due to the surface
`self-cleaning' effect. Our results highlight the potential for parylene as an
alternative ultra-thin insulator in nanoscale electronic devices more broadly,
with potential applications extending into nanobioelectronics due to parylene's
well-established biocompatible properties
Conditional quantum-state transformation at a beam splitter
Using conditional measurement on a beam splitter, we study the transformation
of the quantum state of the signal mode within the concept of two-port
non-unitary transformation. Allowing for arbitrary quantum states of both the
input reference mode and the output reference mode on which the measurement is
performed, we show that the non-unitary transformation operator can be given as
an -ordered operator product, where the value of is entirely determined
by the absolute value of the beam splitter reflectance (or transmittance). The
formalism generalizes previously obtained results that can be recovered by
simple specification of the non-unitary transformation operator. As an
application, we consider the generation of Schr\"odinger-cat-like states. An
extension to mixed states and imperfect detection is outlined.Comment: 7 Postscript figures, using Late
A multicentre integration of a computer-led follow-up of prostate cancer is valid and safe
Background
Prostate cancer (CaP) has a rising number of patients requiring routine follow up. In this study, we aimed to test a computer led follow up service for prostate cancer in two UK hospitals. The testing aimed to validate the computer Expert system in making clinical decisions according to the individual patient’s clinical need. The valid model should accurately identify patients with disease recurrence or treatment failure based on their blood test and clinical picture.
Methods
A clinical decision support system (CDSS) was developed from European (EAU) and national (NICE) guidelines along with knowledge acquired from Urologists. This model was then applied in two UK hospitals to review patients post CaP treatment. These patients’ data (n= 200) were then reviewed by two independent Urology consultants (blinded from the CDSS and other consultant’s rating) and the agreement was calculated by kappa statistics for validation. The second objective aimed to verify the system by estimating the system reliability.
Results
The two individual urology consultants identified 12 % & 15% of the patients to have potential disease progression and recommended their referral to the Urology care. The kappa coefficient for the agreement between the CDSS and the 2 consultants was 0.81 (p < 0.001) and 0.84 (p < 0.001). The agreement among both specialist was also high with k = 0.83 (p < 0.001). The system reliability was estimated on all cases and this demonstrated 100% repeatability of the decisions.
Conclusion
The computer led follow up is a valid model for providing safe follow up for prostate cancer
Macroscopically distinct quantum superposition states as a bosonic code for amplitude damping
We show how macroscopically distinct quantum superposition states
(Schroedinger cat states) may be used as logical qubit encodings for the
correction of spontaneous emission errors. Spontaneous emission causes a bit
flip error which is easily corrected by a standard error correction circuit.
The method works arbitrarily well as the distance between the amplitudes of the
superposed coherent states increases.Comment: 4 pages, 2 postscript figures, LaTeX2e, RevTeX, minor changes, 1
reference adde
Commonwealth Marine Reserves Review: Report of the Expert Scientific Panel
The report provides a scientific basis for the declaration and management of the Australian Marine Reserve Syste
Coherent Superposition States as Quantum Rulers
We explore the sensitivity of an interferometer based on a quantum circuit
for coherent states. We show that its sensitivity is at the Heisenberg limit.
Moreover we show that this arrangement can measure very small length intervals
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