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Related papers: Direct bandgap optical transitions in Si nanocryst…

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The gap in semiconductor nanocrystallites has been extensively studied both theoretically and experimentally over the last two decades. We have compared a recent ``state-of-the-art'' theoretical calculation with a recent…

Condensed Matter · Physics 2009-11-07 V. Ranjan , Manish Kapoor , Vijay A. Singh

The effect of deconfinement due to finite band offsets on transport through quantum wires with two constrictions is investigated. It is shown that the increase in resonance linewidth becomes increasingly important as the size is reduced and…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 A. Ramsak , T. Rejec , J. H. Jefferson

We report a simple scheme for direct generation of frequency-bin entangled photon pairs via spontaneous parametric downconversion. Our fabricated nonlinear optical crystal with two different poling periods can simultaneously satisfy two…

Quantum Physics · Physics 2019-01-28 Fumihiro Kaneda , Hirofumi Suzuki , Ryosuke Shimizu , Keiichi Edamatsu

The case study of a 32-atoms Si nanocrystallite (NC) embedded in a SiO2 matrix, both crystalline and amorphous, or free-standing with different conditions of passivation and strain is analyzed through ab-initio approaches. The Si32/SiO2…

Materials Science · Physics 2010-09-03 Roberto Guerra , Elena Degoli , Margherita Marsili , Olivia Pulci , Stefano Ossicini

Structures and electronic properties of rhombohedral [111] and [110] bismuth nanowires are calculated with the use of density functional theory. The formation of an energy band gap from quantum confinement is studied and to improve…

Mesoscale and Nanoscale Physics · Physics 2017-01-04 Lida Ansari , Farzan Gity , James C. Greer

The dark-matter candidates of particle physics invariably possess electromagnetic interactions, if only via quantum fluctuations. Taken en masse, dark matter can thus engender an index of refraction which deviates from its vacuum value. Its…

High Energy Physics - Phenomenology · Physics 2014-11-18 S. Gardner , D. C. Latimer

Size-dependent quantization of energy spectrum of conducting electrons in solids leads to oscillating dependence of electronic properties on corresponding dimension(s). In conventional metals with typical energy Fermi EF~1 eV and the charge…

Mesoscale and Nanoscale Physics · Physics 2016-11-22 Egor A. Sedov , Kari-Pekka Riikonen , Konstantin Yu. Arutyunov

We investigate the modification of the spontaneous emission dynamics and external quantum efficiency for self-assembled InGaAs quantum dots coupled to extended and localised photonic states in GaAs 2D-photonic crystals. The 2D-photonic…

Materials Science · Physics 2009-11-13 M. Kaniber , A. Kress , M. Bichler , R. Meyer , M. -C. Amann , J. J. Finley

We studied the evolution of the electronic structure across the quantum critical point in V doped Cr employing high resolution photoemission spectroscopy. Experimental results exhibit signatures of pseudogap and orbital Kondo resonance peak…

Strongly Correlated Electrons · Physics 2012-04-04 Ganesh Adhikary , R. Bindu , Sudhir K. Pandey , Kalobaran Maiti

Radiation loss and resonant frequency shift due to sidewall surface roughness of circular and square high-contrast microcavities are estimated and compared by using a boundary integral equations method. An effect of various harmonic…

We report on the observation of spontaneous bursts of coherent radiation from a quantum-degenerate gas of nonequilibrium electron-hole pairs in semiconductor quantum wells. Unlike typical spontaneous emission from semiconductors, which…

Mesoscale and Nanoscale Physics · Physics 2013-12-17 J. -H. Kim , G. T. Noe , S. A. McGill , Y. Wang , A. K. Wojcik , A. A. Belyanin , J. Kono

We investigate the effect of small spatiotemporal modulations in subwavelength-dimensioned phononic crystals with large band gaps, on the frequency spectrum for elastic waves polarized in the plane of periodicity. When the radius of…

Applied Physics · Physics 2021-01-18 D. Psiachos , M. M. Sigalas

With the ever-increasing sophistication of codes, the verification of the implementation of advanced theoretical formalisms becomes critical. In particular, cross comparison between different codes provides a strong hint in favor of the…

Materials Science · Physics 2013-12-24 S. Poncé , G. Antonius , P. Boulanger , E. Cannuccia , A. Marini , M. Côté , X. Gonze

Point-contact measurements on the carbon-substituted Mg(B$_{1-x}$C$_x$)$_2$ filament/powder samples directly reveal a retention of the two superconducting energy gaps in the whole doping range from $x = 0$ to $x \approx 0.1$. The large gap…

Superconductivity · Physics 2009-01-08 Z. Holanova , P. Szabo , P. Samuely , R. H. T. Wilke , S. L. Bud'ko , P. C. Canfield

In a spontaneously dimerized quantum antiferromagnet, spin-1/2 excitations (spinons) are confined in pairs by strings akin to those confining quarks in non-abelian gauge theories. The system has multiple degenerate ground states (vacua) and…

High Energy Physics - Theory · Physics 2017-10-11 Tin Sulejmanpasic , Hui Shao , Anders W. Sandvik , Mithat Unsal

By a rigorous numerical simulation based on the standard multiple scattering theory, we investigate the optical transmission in photonic crystal structures, formed by dielectric cylinders embedded in parallel in a uniform medium. In…

Condensed Matter · Physics 2007-05-23 C. -H. Kuo , Z. Ye

The authors theoretically investigate quantum confinement and transition energies in quantum wells (QWs) asymmetrically positioned in wrinkled nanomembranes. Calculations reveal that the wrinkle profile induces both blue- and redshifts…

Mesoscale and Nanoscale Physics · Physics 2012-06-14 P. Cendula , S. Kiravittaya , O. G. Schmidt

Quantum optics experiments on "bright" beams typically probe correlations between side-band modes. However the extra degree of freedom represented by this dual mode picture is generally ignored. We demonstrate the experimental operation of…

Quantum nanophotonics has become a new research frontier where quantum optics is combined with nanophotonics in order to enhance and control the interaction between strongly confined light and quantum emitters. Such progress provides a…

Mesoscale and Nanoscale Physics · Physics 2012-12-03 Peter Lodahl , Søren Stobbe

We have performed first-principles calculations of Si/SiO$_2$ superlattices in order to examine their electronic states, confinement and optical transitions, using linearized-augmented-plane-wave techniques and density-functional theory.…

Materials Science · Physics 2009-11-07 Pierre Carrier , Laurent J. Lewis , M. W. Chandre Dharma-wardana