English
Related papers

Related papers: Effect of n- and p-type Doping on Coherent Phonons…

200 papers

The dynamics of an exciton-LO-phonon system after an ultrafast optical excitation in an InAs/GaAs quantum dot is studied theoretically. Influence of anharmonic phonon damping and its interplay with the phonon dispersion is analyzed. The…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Pawel Machnikowski , Lucjan Jacak

The impact of electrostatic doping level on the dissipative transport of Armchair GNR-TFET is studied using the Quantum Perturbation Theory (QPT) with the Extended Lowest Order Expansion (XLOE) implementation method. Results show that the…

Mesoscale and Nanoscale Physics · Physics 2020-01-08 Weixiang Zhang , Tarek Ragab , Ji Zhang , Cemal Basaran

We report detailed measurements of composition as well as temperature dependence of the phonon density-of-states in a new series of FeAs compounds with composition CaFe1\_{1-x}Co\_{x}AsF (x = 0, 0.06, 0.12). The composition as well as…

In this paper, we study band-to-band and intersubband characteristics of GaN/AlN heterostructures (planar and nanowires) structurally designed to absorb in the short-wavelength infrared region, particularly at 1.55 microns. We compare the…

Materials Science · Physics 2018-12-03 A. Ajay , C. B. Lim , D. A. Browne , J. Polaczynski , E. Bellet-Amalric , J. Bleuse , M. I. den Hertog , E. Monroy

We study the effects of Kohn anomalies on the superconducting properties in electron- and hole-doped cases of monolayer blue phosphorene, considering both adiabatic and non-adiabatic phonon dispersions using first-principles calculations.…

Superconductivity · Physics 2022-10-05 Mohammad Alidoosti , Davoud Nasr Esfahani , Reza Asgari

In this work we investigate doping and temperature dependences of electronic structure of system with strong electronic correlations and strong electron-phonon interaction modeling cuprates in the frameworks of the three-band p-d-Holstein…

Strongly Correlated Electrons · Physics 2016-12-09 I. A. Makarov , S. G. Ovchinnikov

We present an {\it ab initio} study of the recently discovered superconductivity of boron doped diamond within the framework of a phonon-mediated pairing mechanism. The role of the dopant, in substitutional position, is unconventional in…

Superconductivity · Physics 2009-11-10 Xavier Blase , Ch Adessi , Damien Connetable

We investigate the evolution of the Raman spectrum of defected graphene as a function of doping. Polymer electrolyte gating allows us to move the Fermi level up to 0.7eV, as monitored by \textit{in-situ} Hall-effect measurements. For a…

Materials Science · Physics 2014-10-14 M. Bruna , A. K. Ott , M. Ijas , D. Yoon , U. Sassi , A. C. Ferrari

Superconductivity of doped SrTiO3 is proven to be a particular case of the broader concept of the non-adiabatic pairing mediated by phonons with frequency comparable or larger the Fermi energy. We argue that, for carrier concentrations…

Superconductivity · Physics 2022-06-08 Lev P. Gor'kov

We have examined the effect of pump-probe photon energy on the amplitude of coherent optical phonons in a prototypical phase change material using a femtosecond time-resolved transmission technique. The photon energy was varied between 0.8…

Materials Science · Physics 2017-09-26 T. Suzuki , Y. Saito , P. Fons , A. V. Kolobov , J. Tominaga , M. Hase

Phonon or electron mediated weak BCS attraction is enough to have high critical temperature if a van Hove anomaly is at work. This could apply to electron doped compounds and also to compounds with CuO$_2$ planes overdoped in holes, where…

Superconductivity · Physics 2007-05-23 J. Friedel , M. Kohmoto

We report results of Brillouin - Mandelstam spectroscopy of transparent alumina crystals with Nd dopants. The ionic radius and atomic mass of Nd atoms are distinctively different from those of the host Al atoms. Our results show that even a…

Aliovalent doping has been adopted to optimize the electrical properties of semiconductors, while its impact on the phonon structure and propagation is seldom paid proper attention to. This work reveals that aliovalent doping can be much…

Raman and infrared absorption spectra of Mg(1-x)Al(x)B(2) have been collected for 0<x<0.5 in the spectral range of optical phonons. The x-dependence of the peak frequency, the width and the intensity of the observed Raman lines has been…

Superconductivity · Physics 2009-11-07 P. Postorino , A. Congeduti , P. Dore , A. Nucara , A. Bianconi , D. Di Castro , S. De Negri , A. Saccone

We report a study of the lattice dynamics in superconducting NaFeAs (Tc = 8 K) and doped NaFe0.97Co0.03As (Tc = 20 K) using Raman light scattering. Five of the six phonon modes expected from group theory are observed. In contrast with…

Superconductivity · Physics 2016-11-25 Y. J. Um , Yunkyu Bang , B. H. Min , Y. S. Kwon , M. Le Tacon

We compute, from first-principles, the frequency of the E2g, Gamma phonon (Raman G-band) of graphene, as a function of the charge doping. Calculations are done using i) the adiabatic Born-Oppenheimer approximation and ii) time-dependent…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Michele Lazzeri , Francesco Mauri

We present a study of germanium as n-type dopant in wurtzite GaN films grown by plasma-assisted molecular beam epitaxy, reaching carrier concentrations of up to 6.7E20 cm-3 at 300K, well beyond the Mott density. The Ge concentration and…

We present measurements of low frequency charge noise and conductance drift in modulation doped GaAs/AlGaAs heterostructures grown by molecular beam epitaxy in which the silicon doping density has been varied from $2.4\times 10^{18}…

Mesoscale and Nanoscale Physics · Physics 2018-03-21 S. Fallahi , J. R. Nakamura , G. C. Gardner , M. M. Yannell , M. J. Manfra

We analyze the effect of electron-phonon coupling on photoemission properties and ultrafast response of doped monolayer MoS2. The analysis is based on combined DFT and many-body (Eliashberg theory) approaches. In particular, we have…

Materials Science · Physics 2015-02-02 Neha Nayyar , Duy Le , Volodymyr Turkowski , Talat S. Rahman

Semiconductor heterostructures based on layered two-dimensional transition metal dichalcogenides (TMD) interfaced to gallium nitride (GaN) are excellent material systems to realize broadband light emitters and absorbers. The surface…