Abstract

In meso/nanoscopic systems three significant issues are of pivotalimportance: (i) due to the smallness of their size, quantum effects arecrucial, (ii) for the same reason, the surface-to-volume ratio is largeand this characteristic feature induces certain unique and fascinatingeffects, and (iii) the system remains in active contact with itsenvironment, which induces a variety of novel properties. In view of theenormity of this subject, we shall limit our discussions to certainessential and fundamental science, with a number of non-trivial examples.We shall highlight current activity on various issues mainly related toelectron transport in meso/nano systems. Models relevant to the latterhave some real application to molecular electronics.

Abstract

Abstract

Wave vector-resolved inverse photoelectron spectroscopy (IPES)measurements have been used to demonstrate that there is a large variationof interfacial charge transfer between the supporting substrate andgraphene. The results were obtained for graphene grown by chemical vapordeposition(CVD) on a range of dielectric or metallic substrates. Monolayer graphenegrown by CVD on monolayer BN(0001)/Ru(0001) exhibits strong chargetransfer from the substrate to graphene of 0.07(1) e- per carbon atom,evident from the filling of the π* band and displacement of the Fermilevel. Inversephotoelectron spectroscopy (IPES) measurements of CVD single layergraphene on Ru indicate a substrate-to-graphene charge transfer from thesubstrate of 0.06(1) e- per carbon atom, in agreement with reportedangle-resolved photoemission results. The IPES spectra of CVD single layergraphene onNi(polycystalline), and on Cu(polycystalline) indicate 0.03(1) e- percarbon atom charge transfer from Ni and Cu substrates. IPES measurementsindicate that single layer graphene on MgO(111) exhibit 0.02(1) e- percarbon atom charge is transferred from graphene to the MgO substrate.Additionally, IPES and photoemission data, when combined, along withcharging in the retarding potential vacuum diode geometry indicate thatsingle layer graphene/MgO(111) exhibits a band gap. These data demonstratethat IPES is one effective method for precise measurement ofsubstrate/graphene charge transfer and related electronic interactions, inpart because of the extreme surface sensitivity of the technique. Lookingto the future, comparison of graphene electronic structure on manysubstrates may suggest new strategies for extrinsic doping of graphene forcontrolled mobilities for device applications. The opening of a band gapcan be related to a reduction in symmetry from C6 to C3 or looking at itanother way, making the A and B site of graphene chemically inequivalent.Graphene is not simply chemically inert. We find that the photoemissionand inverse photoemission final states are better screened for dipolarmolecules, with a large intrinsic dipole of 10 Debyes, on gold than isobserved to be the case on graphene on copper, and this is evident in alarger highest occupied molecular orbital to lowest unoccupied molecularorbital gap.Work done with Lingmei Kong,1 Cameron Bjelkevig,2 Sneha Gaddam,2 Mi Zhou,2Young Hee Lee,3 Gang Hee Han,3 Hae Kyung Jeong,4 Ning Wu,1 ZhengzhengZhang,1 Jie Xiao,1 and Jeffry A. Kelber21) University of Nebraska-­‐Lincoln2) University of North Texas.3) Sungkyunkwan University, Suwon, 440-­‐746 Korea (ROK)4) Daegu University, Gyeongsan, 712-­‐714 Korea (ROK)

Abstract

LHC being a hadron machine final states withmulti-leptons are rare compared to multi-jet final states.In the standard model the events become more rare asthe lepton multiplicity increases in the final state. I showthat such final states turn out to be excellent probes fordiscovering new physics beyond the standard model. Ialso show how different kinematic properties of such leptonicfinal states can help in distinguishing different speculativeideas of new physics.

Abstract

First of all, we will take a look at our present global understanding of theneutrino mass-mixing parameters and will identify the major unknowns in this sector.Then we will discuss the physics reach of the upcoming reactor and acceleratorneutrino oscillation experiments in addressing these unsolved issues.Next, we will analyze the impact of large theta(13) on the optimization offuture long baseline superbeam experiments with a special emphasis onpotential European scenarios which are proposed to enhance our knowledgeof neutrino oscillations well beyond what can be anticipated from ongoing andplanned experiments worldwide.