English
Related papers

Related papers: Tuning topological disorder in MgB$_{2}$

200 papers

Topological insulators are bulk semiconductors that manifest in-gap massless Dirac surface states due to the topological bulk-boundary correspondence principle [1-3]. These surface states have been a subject of tremendous ongoing interest,…

Topological photonics has recently emerged as a route to realize robust optical circuitry, and nonlinear effects are expected to enable tunability of topological states with the light intensity. Here we realize experimentally nonlinear…

Broadening of the Raman scattering (RS) spectra was studied in monolayer graphene samples irradiated with various dose of ions followed by annealing of radiation damage at different temperatures. It is shown that the width {\Gamma} (full…

Mesoscale and Nanoscale Physics · Physics 2019-12-13 I. Shlimak , A. Butenko , E. Kogan , M. Kaveh

Electronic Raman scattering measures a polarization-dependent scattering intensity which can provide information about the location of nodes in the energy gap of an unconventional superconductor as well as its overall symmetry. In this…

Superconductivity · Physics 2010-10-06 G. R. Boyd , P. J. Hirschfeld , T. P. Devereaux

The effects of Al substitution and neutron irradiation on the conduction regime (clean or dirty) of the $\pi$- and $\sigma$-band of MgB$_{2}$ have been investigated by means of far-infrared spectroscopy. The intensity reflected by well…

Superconductivity · Physics 2009-11-10 M. Ortolani , D. Di Castro , P. Postorino , I. Pallecchi , M. Monni , M. Putti , P. Dore

We investigate the effect of isotope substitution on the electron-phonon interaction in the multi-band superconductor MgB2 using tunable laser based Angle Resolved Photoemission Spectroscopy. The kink structure around 70 meV in the $\sigma$…

An analytical study is presented of the double resonant Raman scattering process in graphene, responsible for the D and D$^{\prime}$ features in the Raman spectra. This work yields analytical expressions for the D and D$^{\prime}$…

Mesoscale and Nanoscale Physics · Physics 2015-01-29 J. F. Rodriguez-Nieva , E. B. Barros , R. Saito , M. S. Dresselhaus

Raman spectroscopy is a fast, non-destructive means to characterize graphene samples. In particular, the Raman spectra show a significant dependence on doping. While the change in position and width of the G peak can be explained by the…

Materials Science · Physics 2015-05-13 D. M. Basko , S. Piscanec , A. C. Ferrari

A correlated material in the vicinity of an insulator-metal transition (IMT) exhibits rich phenomenology and variety of interesting phases. A common avenue to induce IMTs in Mott insulators is doping, which inevitably leads to disorder.…

The vibrational modes of some single wall carbon nanotube (SWNT) intramolecular junctions (IMJs) have been calculated using the newest Brenner reactive empirical bond order (REBO) potential, based upon which their nonresonant Raman spectra…

Mesoscale and Nanoscale Physics · Physics 2007-07-31 Gang Wu , Jinming Dong

Disordered carbon often exhibit a complex Raman spectrum, with four to six components. Here, a large variety of disordered carbons, forming a collection of samples with a great variety of structures, are analysed using multi-wavelength…

Chemical Physics · Physics 2014-01-14 Cedric Pardanaud , C. Martin , P. Roubin

We investigate the effects of point and line defects in monolayer graphene within the framework of the Hubbard model, using a self-consistent mean field theory. These defects are found to induce characteristic patterns into the electronic…

Mesoscale and Nanoscale Physics · Physics 2011-04-22 Yi Chen Chang , Stephan Haas

Temperature-dependent Raman spectra of TbMnO$_3$ from 5 K to 300 K in the spectral range of 200 to 1525 cm$^{-1}$ show five first-order Raman allowed modes and two high frequency modes. The intensity ratio of the high frequency Raman band…

Strongly Correlated Electrons · Physics 2010-04-12 Pradeep Kumar , Surajit Saha , D. V. S. Muthu , J. R. Sahu , A. K. Sood , C. N. R. Rao

Controlled defect creation is a prerequisite for the detailed study of disorder effects in materials. Here, we irradiate a graphene/Ir(111)-interface with low-energy Ar+ to study the induced structural changes. Combining computer…

Materials Science · Physics 2013-11-01 E. H. Åhlgren , S. K. Hämäläinen , O. Lehtinen , P. Liljeroth , J. Kotakoski

In this study, we employed a Raman spectroscopic analysis of the amide I band of polymerized samples of tubulin exposed to pulsed low-intensity NIR radiation (810 nm, 10 Hz, 22.5 J/cm$^{2}$ dose). Peaks in the Raman fingerprint region…

In this work, we investigate the effect of disorder on the topological properties of multichannel superconductor nanowires. While the standard expectation is that the spectral gap is closed and opened at transitions that change the…

Mesoscale and Nanoscale Physics · Physics 2017-03-16 B. Pekerten , A. Teker , O. Bozat , M. Wimmer , I. Adagideli

The electronic structure of electron-doped polycrystalline Mg$_{1-x}$Al$_{x}$(B$_{1-y}$C$_{y}$)$_2$ was examined by electron energy-loss spectroscopy (EELS) in a scanning transmission electron microscope (STEM) and first-principle…

Superconductivity · Physics 2007-05-23 R. F. Klie , J. C. Zheng , Y. Zhu , A. J. Zambano , L. D. Cooley

Phonon-phonon anharmonic effects have a strong influence on the phonon spectrum; most prominent manifestation of these effects are the softening (shift in frequency) and broadening (change in FWHM) of the phonon modes at finite temperature.…

The search of new means of generating and controlling topological states of matter is at the front of many joint efforts, including bandgap engineering by doping and light-induced topological states. Most of our understading, however, is…

Mesoscale and Nanoscale Physics · Physics 2018-07-19 Hernan L. Calvo , Javier S. Luna , Virginia Dal Lago , Luis E. F. Foa Torres

The unusual Raman spectrum of MgB$_2$ and its formidable temperature dependence are successfully reproduced by means of a parameter-free \emph{ab initio} nonadiabatic theory that accounts for the electron-hole pair scattering mechanisms…

Materials Science · Physics 2018-08-01 Dino Novko