Multiwalled carbon nanotubes (MWNTs) have unique mechanical properties and are ideal candidates for high-performance composites. Elastic measurements, performed with an atomic force microscope, described MWNTs produced by two methods: the arc-discharge method thermal decomposition of hydrocarbons in presence catalysts. Extended stacking defects, such as second production (which unlike first can yield almost continuous long fibers), shown to a much larger effect than point defects on elastic...

The quantum superposition principle states that an entity can exist in two different simultaneously, counter to our 'classical' intuition. Is it possible understand a given system's behaviour without such concept? A test designed by Leggett and Garg rule out this possibility. test, originally intended for macroscopic objects, has been implemented various systems. However date no experiment employed the 'ideal negative result' measurements are required most robust test. Here we introduce...

Quantum effects in nanoscale electronic devices promise to lead new types of functionality not achievable using classical components. However, quantum behaviour also presents an unresolved challenge facing electronics at the few-nanometre scale: resistive channels start leaking owing tunnelling. This affects performance transistors, with direct source-drain tunnelling degrading switching ratios and subthreshold swings, ultimately limiting operating frequency due increased static power...

We have determined the mechanical anisotropy of a single microtubule by simultaneously measuring Young's and shear moduli in vitro. This was achieved elastically deforming deposited on substrate tailored electron-beam lithography with tip an atomic force microscope. The modulus is 2 orders magnitude lower than Young's, giving rise to length-dependent flexural rigidity microtubules. temperature dependence microtubule's bending stiffness (5-40) degrees C range shows strong variation upon...

This Account focuses on structural and dynamic behavior of molecules encapsulated in carbon nanotubes. The impact the confinement molecular packing, orientation, translation, rotation, reactivity is demonstrated for a range fullerene nonfullerene molecules. These phenomena are described analyzed using current understanding molecule-nanotube intermolecular interactions.

Quantum-Enhanced Measurement The single electron spin in a molecule, atom, or quantum dot precesses magnetic field and so can be used as sensor. As the number of spins sensor increases, too does sensitivity. Quantum mechanical entanglement ensemble should then allow sensitivity to increase much more than would expected from simple individual ensemble. Using highly symmetric trimethyl phosphite, molecule containing central P atom surrounded by nine hydrogen atoms, Jones et al. (p. 1166 ,...

This paper describes a study of adhesion between elastic solids and in particular the effect tangential force upon size contact area. In first part paper, relation stress intensity factor normally loaded overall energy balance approach is discussed. second main an analysis given for influence on adhesive contact. The equation derived to describe its has been verified by experiments carried out rubber hemispheres pressed against glass flat. experimental results show qualitatively clear...

Few layer graphene nanostructures are directly imaged using aberration corrected high-resolution transmission electron microscopy with an accelerating voltage of 80 kV. We observe rotational stacking faults in the HRTEM images 2-6 layers sheets, giving rise to Moir patterns. By filtering frequency domain a Fourier transform, we reconstruct lattice each sheet and determine packing structure relative orientations up six separate sets. Direct evidence is obtained for few sheets that different...

Molecular structures appear to be natural candidates for a quantum technology: individual atoms can support superpositions long periods, and such in principle embedded permanent molecular scaffolding form an array. This would true nanotechnology, with dimensions of order nanometre. However, the challenges realizing vision are immense. One must identify suitable elementary unit demonstrate its merits qubit storage manipulation, including input/output. These units then formed into large arrays...

One of the most striking features quantum mechanics is profound effect exerted by measurements alone. Sophisticated control now available in several experimental systems, exposing discrepancies between and classical whenever measurement induces disturbance interrogated system. In practice, such may frequently be explained as back-action required adding noise to a signal. Here, we implement “three-box” game [Aharonov Y, et al. (1991) J Phys A Math Gen 24(10):2315–2328] using state-of-the-art...

A cyclic porphyrin trimer has been synthesized which a high affinity for fullerenes. It forms 1:1 complexes with C(60) and C(70) association constants of 2 x 10(6) 10(8) M(-1), respectively, in toluene. Its affinities C(86) La@C(82) are too strong to measure by fluorescence titration. The solvent dependence the shows that solvation both guest host influence binding strength.

We demonstrate a robust graphene-molecule-graphene transistor architecture.

Charge transport through molecular junctions is often described either as a purely coherent or classical phenomenon, and using the Landauer-Büttiker formalism Marcus theory (MT), respectively. Using generalised quantum master equation, we here derive an expression for current junction modelled single electronic level coupled with collection of thermalised vibrational modes. We demonstrate that aforementioned theoretical approaches can be viewed two limiting cases this more general present...

Since the early days of quantum mechanics, it has been known that electrons behave simultaneously as particles and waves, now electronic devices can harness this duality. When are shrunk to molecular scale, is unclear under what conditions does electron transmission remain phase-coherent, molecules usually treated either scattering or redox centers, without considering wave–particle duality charge carrier. Here, we demonstrate remains phase-coherent in porphyrin nanoribbons connected...

We give three methods for entangling quantum states in dots. do this by showing how to tailor the resonant energy (F\"orster-Dexter) transfer mechanisms and biexciton binding a dot molecule. calculate magnitude of these two electrostatic interactions as function size, interdot separation, material composition, confinement potential, applied electric field using an envelope approximation two-cuboid In first implementation, we show that it is desirable suppress F\"orster coupling create...

We have assembled molecular arrays of C60 inside double-walled carbon nanotubes (DWNTs) with internal diameters 11-26 A and directly observed the existence different crystalline phases previously predicted theoretically. The structure encapsulated crystal is defined by diameter DWNT, as molecules adjust their packing arrangement in order to maximize van der Waals interactions. also shown that fullerenes C(60)@DWNT interact outer layer DWNTs, demonstrated efficient filling DWNTs less than 12 A.

The surface structure of nonstoichiometric ${\mathrm{CeO}}_{2}(111)$ has been studied by scanning tunneling microscopy (STM). By using extremely small currents it was possible to obtain the first ever reported atomically resolved images this oxide. STM imaging at a sample bias voltage between $\ensuremath{-}2$ and $\ensuremath{-}3.5\mathrm{V}$. Comparing with band ceria we claim that main contribution image contrast results from oxygen in topmost layer. dominant defect type on RT is...

The structure of nanometer-sized strained Ge islands epitaxially grown on a Si substrate was studied using ultrasonic force microscopy (UFM), which combines the sensitivity to elastic acoustic with nanoscale spatial resolution atomic microscopy. UFM not only images local surface elasticity variations between dots and about 5 nm, but is also capable detecting strain variation across dot, via modification stiffness.

We describe the growth of InGaN quantum dots (QDs) by metalorganic vapor phase epitaxy. A thin epilayer is grown on a GaN buffer layer and then annealed at temperature in molecular nitrogen inducing dot formation. Microphotoluminescence studies these QDs reveal sharp peaks with typical linewidths ∼700 μeV 4.2 K, linewidth being limited spectral resolution. Time-resolved photoluminescence suggests that excitons structures have lifetimes excess 2 ns K.

We report on a joint experimental and theoretical study of the ordered structures melamine molecules formed Au(111)-(22 × √3) surface. Scanning tunneling microscopy (STM) images taken under UHV conditions reveal two distinct monolayers one which has never been reported before gold. also find that may serve as transition region ("domain wall") between islands by other arrangement. Using state-of-the-art density functional calculations in conjunction with systematic gas-phase analysis based...

A study of the influence surface roughness on net work adhesion when a smooth, high viscoelastic solid is first brought into contact with and then pulled away from roughened Perspex surface. The was observed to be strongly dependent upon rate at which these surfaces were apart. dependence could calculated by normalizing data obtained for normally smooth At small value an increase in observed.