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We study the frequency dependencies in the renormalization of the fermion Greens function for the $\pi$-band electrons in graphene and their influence on the dynamical gap generation at sufficiently strong interaction. Adopting the…

Mesoscale and Nanoscale Physics · Physics 2016-09-07 M. E. Carrington , C. S. Fischer , L. von Smekal , M. H. Thoma

Contrary to the conventional empirical law, band gap of dilute nitride semiconductors decreases with nitrogen concentration. In spite of a number of investigations, origin of this "large band gap bowing", is still under debate. In order to…

Materials Science · Physics 2016-02-17 Masato Morifuji , Fumitaro Ishikawa

The near-field and far-field spectral response of plasmonic systems are often assumed to be identical, due to the lack of methods that can directly compare and correlate both responses under similar environmental conditions. We develop a…

By independently engineering strain and composition, this work demonstrates and investigates direct band gap emission in the mid-infrared range from GeSn layers grown on silicon. We extend the room-temperature emission wavelength above ~4.0…

${\beta}$-LiGaO$_2$ with an orthorhombic wurtzite-derived structure is a candidate ultrawide direct-bandgap semiconductor. In this work, using the non-adiabatic Allen-Heine-Cardona approach, we investigate the bandgap renormalization…

Materials Science · Physics 2023-05-30 Dangqi Fang

Unique optical properties of colloidal semiconductor quantum dots (QDs), arising from quantum mechanical confinement of charge within these structures, present a versatile testbed for the study of how high electric fields affect the…

We present the first observations of zero-n bandgaps in photonic crystal superlattices consisting of alternating stacks of negative index photonic crystals and positive index dielectric materials in the near-infrared. Guided by ab initio…

Electronic structures of wurtzite GaAs nanowires in the [0001] direction were studied using first-principles calculations. It was found that the band gap of GaAs nanowires experience a direct-to-indirect transition when the diameter of the…

Materials Science · Physics 2012-08-07 Andrew Copple , Nathaniel Ralston , Xihong Peng

Atoms coupled to optical fields confined in one and two spatial dimensions in solid state microstructures can experience very large light shifts if the driving frequencies are close to a resonance of the microstructures and an atomic…

Quantum Physics · Physics 2009-11-07 Peter Horak , Peter Domokos , Helmut Ritsch

We study effects of electron-electron interactions and confinement potential on the magneto-optical absorption spectrum in the far-infrared range of lateral quantum dot molecules. We calculate far-infrared (FIR) spectra for three different…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 M. Helle , A. Harju , R. M. Nieminen

We demonstrate the simultaneous quantum state reconstruction of the spectral modes of the light field emitted by a continuous wave degenerate optical parametric amplifier. The scheme is based on broadband measurement of the quantum…

Quantum Physics · Physics 2009-10-31 Gerd Breitenbach , Fabrizio Illuminati , Stephan Schiller , Jurgen Mlynek

Frequency shifts of red- and blue-scattered (Stokes/anti-Stokes) side-bands in quantum optomechanics are shown to be counter-intuitively inequal, resulting in an unexpected symmetry breaking. This difference is referred to as Side-band…

Quantum Physics · Physics 2019-06-25 Sina Khorasani

The finite momentum transfer ($\boldsymbol{q}$) longitudinal optical response $\sigma^L(\boldsymbol{q},\omega)$ of graphene has a peak at an energy $\omega=\hbar v_F q$. This corresponds directly to a quasiparticle peak in the spectral…

Mesoscale and Nanoscale Physics · Physics 2013-01-11 J. P. Carbotte , J. P. F. LeBlanc , Phillip E. C. Ashby

An anomalous large level shift is newly found to correct the one-electron spectrum of a closed-shell carbon nanocluster, for example, the spectrum which was described within the model of a thin quantum well rolled into a sphere. As a result…

Materials Science · Physics 2016-08-31 Slava V. Rotkin

In weakly nonlinear systems, the main effect of cubic nonlinearity on wave propagation is an amplitude-dependent correction of the dispersion relation. This phenomenon can manifest either as a frequency shift or as a wavenumber shift…

Pattern Formation and Solitons · Physics 2021-07-27 Weijian Jiao , Stefano Gonella

We investigate the optical properties of a photonic crystal composed of a quasi-one-dimensional flat-band lattice array through finite-difference time-domain simulations. The photonic bands contain flat bands (FBs) at specific frequencies,…

We analyze the effect of low dimensionality on the electrical conductivity ({\sigma}) and Seebeck coefficient (S) in ultra-narrow Si nanowires (NWs) by employing atomistic considerations for the electronic structures and linearized…

Materials Science · Physics 2015-06-16 Neophytos Neophytou , Hans Kosina

The ability to interferometrically detect inertial rotations via the Sagnac effect has been a strong stimulus for the development of atom interferometry because of the potential 10^{10} enhancement of the rotational phase shift in…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Chris P. Search , John R. E. Toland , Marko Zivkovic

Narrow optical resonances of atoms or molecules have immense significance in various precision measurements, such as testing fundamental physics and the generation of primary frequency standards. In these studies, accurate transition…

Atomic Physics · Physics 2022-10-13 Y. -N. Lv , A. -W. Liu , Y. Tan , C. -L. Hu , T. -P. Hua , X. -B. Zou , Y. R. Sun , C. -L. Zou , G. -C. Guo , S. -M. Hu

InSe, a member of the layered materials family, is a superior electronic and optical material which retains a direct bandgap feature from the bulk to atomically thin few-layers and high electronic mobility down to a single layer limit. We,…