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Unexpected change in the electronic properties of the Au-graphene interface caused by toluene
Author(s): H. Pinto, R. Jones, J. P. Goss, and P. R. Briddon
Density-functional theory is used to show that isolated Au atoms on graphene do not lead to substantial charge transfer or doping but this is altered if a second layer of graphene or toluene is present. Thus intercalating Au into a sandwich of graphene-toluene leads to n -type doping of graphene. Th...
[Phys. Rev. B 82, 125407] Published Fri Sep 03, 2010
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Density functional theory screened-exchange approach for investigating electronical properties of graphene-related materials
Author(s): Roland Gillen and John Robertson
We present ab initio calculations of the band structure of graphene and of short zigzag graphene nanoribbons (ZGNRs) by the screened-exchange-local-density approximation (LDA) method within the framework of density functional theory. The inclusion of nonlocal electron-electron interactions in this a...
[Phys. Rev. B 82, 125406] Published Fri Sep 03, 2010
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Reversed polarized emission in highly strained a -plane GaN/AlN multiple quantum wells
Author(s): R. Mata, A. Cros, J. A. Budagosky, A. Molina-S?hez, N. Garro, A. Garc?Crist?, J. Renard, S. Founta, B. Gayral, E. Bellet-Amalric, C. Bougerol, and B. Daudin
The polarization of the emission from a set of highly strained a -plane GaN/AlN multiple quantum wells of varying well widths has been studied. A single photoluminescence peak is observed that shifts to higher energies as the quantum well thickness decreases due to quantum confinement. The emitted l...
[Phys. Rev. B 82, 125405] Published Fri Sep 03, 2010
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Optoelectronic properties of graphene in the presence of optical phonon scattering
Author(s): W. Xu, H. M. Dong, L. L. Li, J. Q. Yao, P. Vasilopoulos, and F. M. Peeters
We study in detail the optoelectronic properties of graphene. Considering the electron interactions with photons and phonons, we employ the mass- and energy-balance equations to self-consistently evaluate the photoinduced carrier densities, the optical conductance, and the transmission coefficient i...
[Phys. Rev. B 82, 125304] Published Fri Sep 03, 2010
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Local structure of indium in quinary (InGa)(AsSbN)/GaAs quantum wells
Author(s): Jingli Chen, Gianluca Ciatto, Melanie Le Du, Jean-Christophe Harmand, and Frank Glas
We performed In?K -edge x-ray absorption fine-structure spectroscopy on (InGa)(AsSbN)/GaAs quinary quantum well samples exposed to annealing of different durations, in order to investigate their microstructures. Spectra neither evidence large modification as a function of annealing, nor are sensit...
[Phys. Rev. B 82, 125303] Published Fri Sep 03, 2010
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Decoherence by electromagnetic fluctuations in double-quantum-dot charge qubits
Author(s): Diego C. B. Valente, Eduardo R. Mucciolo, and F. K. Wilhelm
We discuss decoherence due to electromagnetic fluctuations in charge qubits formed by two lateral quantum dots. We use effective circuit model to evaluate correlations of voltage fluctuations in the qubit setup. These correlations allows us to estimate energy (T_{1} ) and phase (T_{2} ) relaxation t...
[Phys. Rev. B 82, 125302] Published Fri Sep 03, 2010
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Nitrogen composition dependence of electron effective mass in GaAs_{1?x} N_{x}
Author(s): T. Dannecker, Y. Jin, H. Cheng, C. F. Gorman, J. Buckeridge, C. Uher, S. Fahy, C. Kurdak, and R. S. Goldman
We have investigated the N composition, x , and temperature, T , dependence of the electron effective mass, m^{?} , of GaAs_{1?x} N_{x} films with sufficiently low carrier concentration that carriers are expected to be confined to near the bottom of the conduction-band edge (CBE). Using Seebeck ...
[Phys. Rev. B 82, 125203] Published Fri Sep 03, 2010
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First-principles investigation on redox properties of M -doped CeO_{2} (M=Mn,Pr,Sn,Zr)
Author(s): Yuanhao Tang, Hua Zhang, Lixia Cui, Chuying Ouyang, Siqi Shi, Weihua Tang, Hong Li, Jong-Sook Lee, and Liquan Chen
The effects of M (M=Mn,Pr,Sn,Zr) doping on the redox thermodynamics of CeO_{2} have been investigated using first-principles density-functional theory calculations with the on-site Coulomb interaction taken into account. Two different mechanisms for the O-vacancy formation in doped CeO_{2} have been...
[Phys. Rev. B 82, 125104] Published Fri Sep 03, 2010
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Collective phonon excitation in KTaO_{3}
Author(s): Akitoshi Koreeda, Ryuta Takano, Akira Ushio, and Seishiro Saikan
The collective excitation of phonons, including thermal diffusion and second sound (temperature wave), in KTaO_{3} has been studied by low-frequency light-scattering and by time-domain light-scattering techniques. The observed spectra are analyzed with the new spectral formula, which is applicable c...
[Phys. Rev. B 82, 125103] Published Fri Sep 03, 2010
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Dielectric screening and band-structure effects in low-energy photoemission
Author(s): E. E. Krasovskii, V. M. Silkin, V. U. Nazarov, P. M. Echenique, and E. V. Chulkov
Nonlocal response of the surface to the incident light is included into an ab initio one-step photoemission theory. Surface-state normal emission spectra from Be(0001) and Al(100) are calculated by a full-potential scattering method and are found to agree well with the experiment in a wide energy ra...
[Phys. Rev. B 82, 125102] Published Fri Sep 03, 2010
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