UScholar Works
 
Filters: Journal Title: "Physical Review B" Collection: "ir_uspace"
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CreatorTitleDescriptionSubjectDate
1 Liu, FengDetermination of the Ehrlich-Schwoebel barrier in epitaxial growth of thin filmsWe demonstrate an approach for determining the "effective" Ehrlich-Schwoebel (ES) step-edge barrier, an important kinetic constant to control the interlayer mass transport in epitaxial growth of thin films. The approach exploits the rate difference between the growth and/or decay of an adatom and a...Ehrlich-Schwoebel barrier; Epitaxial growth; Step-edge barrier; Adatoms2006-11
2 Mishchenko, Eugene; Raikh, Mikhail E.Electrostatics of straight and bent single-walled carbon nanotubesResponse of a single-walled carbon nanotube to external electric field, F, is calculated analytically within the classical electrostatics. Field-induced charge density distribution is approximately linear along the axis of a metallic nanotube and depends rather weakly, as ln(h/ r), on the nanotube...Electrostatics2006-10
3 Lupton, John MarkEvidence for temperature-independent triplet diffusion in a ladder-type conjugated polymerWe study the temperature dependence of triplet formation and decay by considering the phosphorescence dynamics in a prototypical conjugated polymer matrix. The dynamics of triplet formation as a function of temperature are unraveled by applying an electric field during optical singlet generation a...Triplet diffusion; Triplet excitons; Ladder-type conjugated polymers; Temperature dependence2006-12
4 Mishchenko, EugeneGapless surfaces in anisotropic superfluidsWe demonstrate when p-wave pairing occurs between species whose free Fermi surfaces are mismatched the gap generally vanishes over a two-dimensional surface. We present detailed calculations of condensation energy, superfluid density (Meissner mass) and specific heat for such states. We also consi...Anisotropic superfluids; Meissner mass2006-11
5 Wu, Yong-ShiGeneral theorem relating the bulk topological number to edge states in two-dimensional insulatorsWe prove a general theorem on the relation between the bulk topological quantum number and the edge states in two-dimensional insulators. It is shown that whenever there is a topological order in bulk, characterized by a nonvanishing Chern number, even if it is defined for a nonconserved quantity s...Edge states; Bulk topology; Chern number2006-07
6 Liu, FengInfluence of quantum size effects on Pb island growth and diffusion barrier oscillationsQuantum size effects are successfully exploited in manipulating the growth of (111) oriented Pb islands on Si(111) substrate with a scanning tunneling microscope. The growth dynamics and morphology displayed can be well controlled through the quantum size effects defined by the island thicknesses ...Quantum size effects; QSE; Pb island; Diffusion barrier oscillations2006-08
7 Wu, Yong-ShiNumerical study of the three-dimensional random-field Ising model at zero and positive temperatureIn this paper the three-dimensional random-field Ising model is studied at both zero temperature and positive temperature. Critical exponents are extracted at zero temperature by finite size scaling analysis of large discontinuities in the bond energy. The heat capacity exponent α is found to be n...Bond energies; Ground states2006-08
8 Liu, FengOrigin of intergranular embrittlement of Al alloys induced by Na and Ca segregation: grain boundary weakeningUsing a first-principles computational tensile test, we show that the ideal tensile strength of an Al grain boundary (GB) is reduced with both Na and Ca GB segregation. We demonstrate that the fracture occurs in the GB interface, dominated by the break of the interfacial bonds. Experimentally, we f...Intergranular embrittlement; Grain boundary; Intergranular fracture2006-06
9 Mishchenko, Eugene; Raikh, Mikhail E.Penetration of external field into regular and random arrays of nanotubes: implications for field emissionWe develop an analytical theory of polarization of a vertically aligned array of carbon nanotubes (NTs) in external electric field. Such arrays are commonly utilized in field-emission devices, due to the known electrostatic effect of strong field enhancement near the tip of an individual NT. A sma...Field-emission current; Fowler-Nordheim law2006-06
10 Vardeny, Zeev ValentinePhotophysics of excitons in quasi-one-dimensional organic semiconductors: single-walled carbon nanotubes and ∏-conjugated polymersThe nature of the primary photoexcitations in semiconducting single-walled carbon nanotubes (S-SWCNTs) is of strong current interest. We have studied the emission spectra of S-SWCNTs and two different rr-conjugated polymers in solutions and films, and have also performed ultrafast pump-probe spectro...Photophysics; Excitons; Quasi-one-dimensional; Single-walled carbon nanotubes; pi-conjugated polymers2006-02
11 Mishchenko, Eugene; Raikh, Mikhail E.Planar array of semiconducting nanotubes in an external electric field: collective screening and polarizabilityWe study theoretically the charge separation in a planar array of semiconducting nanotubes (NTs) of length, 2h, placed in an external electric field, F, parallel to their axes. By employing the conformal mapping, we find analytically the exact distribution of the induced charge density for the arb...Planar array2006-12
12 Mishchenko, EugenePolarized electric current in semiclassical transport with spin-orbit interactionSemiclassical solutions of two-dimensional Schrödinger equation with spin-orbit interaction and smooth potential are considered. In the leading order, spin polarization is in-plane and follows the evolution of the electron momentum for a given subband. Out-of-plane spin polarization appears as a ...Spin-polarized current; Sharvin conductance; Spin-orbit coupling2006-10
13 Mishchenko, EugeneSmall-angle impurity scattering and the spin Hall conductivity in two-dimensional semiconductor systemsAn arbitrarily small concentration of impurities can affect the spin Hall conductivity in a two-dimensional semiconductor system. We develop a Boltzmann-like equation that can be used for impurity scattering with an arbitrary angular dependence, and for an arbitrary angular dependence of the spin-o...Spin Hall conductivity; Impurity scattering; Spin-orbit coupling2006-02
14 Wu, Yong-ShiTopological quantization of the spin Hall effect in two-dimensional paramagnetic semiconductorsWe propose models of two-dimensional paramagnetic semiconductors where the intrinsic spin Hall effect is exactly quantized in integer units of a topological charge. The model describes a topological insulator in the bulk and a "holographic metal" at the edge, where the number of extended edge stat...Topological insulator; Holographic metal; Edge states2006-08
15 Boehme, ChristophTransport and recombination through weakly coupled localized spin pairs in semiconductors during coherent spin excitationSemianalytical predictions for the transients of spin-dependent transport and recombination rates through localized states in semiconductors during coherent electron-spin excitation are made for the case of weakly spin-coupled charge-carrier ensembles. The results show that the on-resonant Rabi freq...Larmor frequency; Larmor separations2006-12
16 Mishchenko, Eugene; Raikh, Mikhail E.Tunneling between two-dimensional electron layers with correlated disorder: anomalous sensitivity to spin-orbit couplingTunneling between two-dimensional electron layers with mutually correlated disorder potentials is studied theoretically. Due to this correlation, the diffusive eigenstates in different layers are almost orthogonal to each other. As a result, a peak in the tunnel I-V characteristics shifts towards s...Spin-orbit coupling2006-11
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