16,590 research outputs found
Direct observation of a highly spin-polarized organic spinterface at room temperature
The design of large-scale electronic circuits that are entirely
spintronics-driven requires a current source that is highly spin-polarised at
and beyond room temperature, cheap to build, efficient at the nanoscale and
straightforward to integrate with semiconductors. Yet despite research within
several subfields spanning nearly two decades, this key building block is still
lacking. We experimentally and theoretically show how the interface between Co
and phthalocyanine molecules constitutes a promising candidate. Spin-polarised
direct and inverse photoemission experiments reveal a high degree of spin
polarisation at room temperature at this interface. We measured a magnetic
moment on the molecules's nitrogen pi orbitals, which substantiates an
ab-initio theoretical description of highly spin-polarised charge conduction
across the interface due to differing spinterface formation mechanims in each
spin channel. We propose, through this example, a recipe to engineer simple
organic-inorganic interfaces with remarkable spintronic properties that can
endure well above room temperature
A comparative study of angle dependent magnetoresistance in [001] and [110]
The angle dependent magnetoresistance study on [001] and [110] LaSrMnO thin films show that the anisotropy energy of [110]
films is higher when compared with a [001] oriented LaSrMnO film of similar thickness. The data has been analyzed in the light
of multidomain model and it is seen that this model correctly explains the
observed behavior.Comment: 8pages, 2 figure
Evanescent single-molecule biosensing with quantum limited precision
Sensors that are able to detect and track single unlabelled biomolecules are
an important tool both to understand biomolecular dynamics and interactions at
nanoscale, and for medical diagnostics operating at their ultimate detection
limits. Recently, exceptional sensitivity has been achieved using the strongly
enhanced evanescent fields provided by optical microcavities and nano-sized
plasmonic resonators. However, at high field intensities photodamage to the
biological specimen becomes increasingly problematic. Here, we introduce an
optical nanofibre based evanescent biosensor that operates at the fundamental
precision limit introduced by quantisation of light. This allows a four
order-of-magnitude reduction in optical intensity whilst maintaining
state-of-the-art sensitivity. It enable quantum noise limited tracking of
single biomolecules as small as 3.5 nm, and surface-molecule interactions to be
monitored over extended periods. By achieving quantum noise limited precision,
our approach provides a pathway towards quantum-enhanced single-molecule
biosensors.Comment: 17 pages, 4 figures, supplementary informatio
Enhancing physicochemical properties of coconut oil for the application of engine lubrication
Engine lubricants require specific physical and chemical properties to function effectively and extend the lifespan of engines. Coconut oil (CCO) is an abundant, renewable, and environmentally friendly bio-based stock that has the potential to be a viable alternative to conventional mineral oil-based lubricants. In this study, we investigated the potential of CCO as a lubricant and formulated different blends with additives to enhance its physicochemical characteristics. Polymethylmethacrylate (PMMA), styrenated phenol (SP) and potassium hydroxide (KOH) were used as additives in varying concentrations. We evaluated the formulations for low pour point (PP), high viscosity index (VI) and total base number (TBN) using differential scanning calorimetry (DSC), viscometry, and titration methods (following ASTM D2270 and ASTM D2896â21 respectively). The formulated CCO was also tested for thermal, oxidative, and shear stability using thermogravimetric analysis and rheometry. The optimal formulation exhibited a PP reduction from 21 °C to 6 °C, improved VI from 169 to 206, and a TBN adjustment from 0 to 4.14 mg KOH g-1. The formulated CCO also exhibited superior thermal, oxidative, and shear stability compared to unformulated CCO and reference oil (15W40). Our results suggest that blending CCO with additives can effectively enhance its suitability for engine lubrication, opening up new possibilities for environmentally sustainable and renewable lubricants
Teleportation as a Depolarizing Quantum Channel, Relative Entropy and Classical Capacity
We show that standard teleportation with an arbitrary mixed state resource is
equivalent to a generalized depolarizing channel with probabilities given by
the maximally entangled components of the resource. This enables the usage of
any quantum channel as a generalized depolarizing channel without additional
twirling operations. It also provides a nontrivial upper bound on the
entanglement of a class of mixed states. Our result allows a consistent and
statistically motivated quantification of teleportation success in terms of the
relative entropy and this quantification can be related to a classical
capacity.Comment: Version published in Phys. Rev. Let
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Numerical modelling of microwave sintering of lunar simulants under near lunar atmospheric condition
Standard Model Top Quark Asymmetry at the Fermilab Tevatron
Top quark pair production at proton-antiproton colliders is known to exhibit
a forward-backward asymmetry due to higher-order QCD effects. We explore how
this asymmetry might be studied at the Fermilab Tevatron, including how the
asymmetry depends on the kinematics of extra hard partons. We consider results
for top quark pair events with one and two additional hard jets. We further
note that a similar asymmetry, correlated with the presence of jets, arises in
specific models for parton showers in Monte Carlo simulations. We conclude that
the measurement of this asymmetry at the Tevatron will be challenging, but
important both for our understanding of QCD and for our efforts to model it.Comment: 26 p., 10 embedded figs., comment added, version to appear in PR
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Microwave Heating of Lunar Simulants JSC-1A and NU-LHT-3M: Experimental And Theoretical Analysis
Non-linear optomechanical measurement of mechanical motion
Precision measurement of non-linear observables is an important goal in all
facets of quantum optics. This allows measurement-based non-classical state
preparation, which has been applied to great success in various physical
systems, and provides a route for quantum information processing with otherwise
linear interactions. In cavity optomechanics much progress has been made using
linear interactions and measurement, but observation of non-linear mechanical
degrees-of-freedom remains outstanding. Here we report the observation of
displacement-squared thermal motion of a micro-mechanical resonator by
exploiting the intrinsic non-linearity of the radiation pressure interaction.
Using this measurement we generate bimodal mechanical states of motion with
separations and feature sizes well below 100~pm. Future improvements to this
approach will allow the preparation of quantum superposition states, which can
be used to experimentally explore collapse models of the wavefunction and the
potential for mechanical-resonator-based quantum information and metrology
applications.Comment: 8 pages, 4 figures, extensive supplementary material available with
published versio
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