Transmission of doughnut light through a bull's eye structure

We experimentally investigate the extraordinary optical transmission of doughnut light through a bull's eye structure. Since the intensity is vanished in the center of the beam, almost all the energy reaches the circular corrugations (not on the hole), excite surface plasmons which propagate through the hole and reradiate photons. The transmitted energy is about 57 times of the input energy on the hole area. It is also interesting that the transmitted light has a similar spatial shape with the input light although the diameter of the hole is much smaller than the wavelength of light.Comment: 3 pages,4 figure

Three-Leaf Dart-Shaped Single-Crystal BN Formation Promoted by Surface Oxygen

Two-dimensional hexagonal boron nitride (h-BN) single crystals with various shapes have been synthesized by chemical vapor deposition over the past several years. Here we report the formation of three-leaf dart (3LD)-shaped single crystals of h-BN on Cu foil by atmospheric-pressure chemical vapor deposition. The leaves of the 3LD-shaped h-BN are as long as 18 {\mu}m and their edges are smooth armchair on one side and stepped armchair on the other. Careful analysis revealed that surface oxygen plays an important role in the formation of the 3LD shape. Oxygen suppressed h-BN nucleation by passivating Cu surface active sites and lowered the edge attachment energy, which caused the growth kinetics to change to a diffusion-controlled mode.Comment: 7 pages,6 figure

Generating entanglement between microwave photons and qubits in multiple cavities coupled by a superconducting qutrit

We discuss how to generate entangled coherent states of four \textrm{microwave} resonators \textrm{(a.k.a. cavities)} coupled by a superconducting qubit. We also show \textrm{that} a GHZ state of four superconducting qubits embedded in four different resonators \textrm{can be created with this scheme}. In principle, \textrm{the proposed method} can be extended to create an entangled coherent state of $n$ resonators and to prepare a Greenberger-Horne-Zeilinger (GHZ) state of $n$ qubits distributed over $n$ cavities in a quantum network. In addition, it is noted that four resonators coupled by a coupler qubit may be used as a basic circuit block to build a two-dimensional quantum network, which is useful for scalable quantum information processing.Comment: 13 pages, 7 figure

Coalescence of Carbon Atoms on Cu (111) Surface: Emergence of a Stable Bridging-Metal Structure Motif

By combining first principles transition state location and molecular dynamics simulation, we unambiguously identify a carbon atom approaching induced bridging metal structure formation on Cu (111) surface, which strongly modify the carbon atom coalescence dynamics. The emergence of this new structural motif turns out to be a result of the subtle balance between Cu-C and Cu-Cu interactions. Based on this picture, a simple theoretical model is proposed, which describes a variety of surface chemistries very well

Grease film evolution in rolling elastohydrodynamic lubrication contacts

Although most rolling element bearings are grease lubricated, the underlying mechanisms of grease lubrication has not been fully explored. This study investigates grease film evolution with glass disc revolutions in rolling elastohydrodynamic lubrication (EHL) contacts. The evolution patterns of the grease films were highly related to the speed ranges and grease structures. The transference of thickener lumps, film thickness decay induced by starvation, and residual layer were recognized. The formation of an equilibrium film determined by the balance of lubricant loss and replenishment was analyzed. The primary mechanisms that dominate grease film formation in different lubricated contacts were clarified. © 2020, The Author(s)

2-(Dibutyl­amino)-3-(4-fluoro­phen­yl)-5,6,7,8-tetra­hydro-7-methyl-6,8-di­phenyl­pyridine­[3′,4′:2,3]thieno[5,4-d]pyrimidin-4(3H)-one

In the crystal structure of the title compound, C36H39FN4OS, the two fused rings of the thienopyrimidine system are coplanar. The 4-fluoro­phenyl ring is twisted with respect to the heterocyclic pyrimidinone ring by 67.21 (14)°. The piperidine ring shows a half-chair conformation. One of the n-butyl chains is disordered equally over two sites. The crystal packing is stabilized by C—H⋯O hydrogen bonds