English
Related papers

Related papers: Excitonic gaps and exciton binding energies in mul…

200 papers

Using a combination of ultraviolet-vacuum ultraviolet reflectivity and spectroscopic ellipsometry, we observe a resonant exciton at an unusually high energy of 6.3eV in epitaxial graphene. Surprisingly, the resonant exciton occurs at room…

We outline a Kohn-Sham-Dirac density-functional-theory (DFT) scheme for graphene sheets that treats slowly-varying inhomogeneous external potentials and electron-electron interactions on an equal footing. The theory is able to account for…

Strongly Correlated Electrons · Physics 2008-09-23 Marco Polini , Andrea Tomadin , Reza Asgari , A. H. MacDonald

The giant exciton binding energy and the richness of degrees of freedom make monolayer transition metal dichalcogenide an unprecedented playground for exploring exciton physics in 2D systems. Thanks to the well energetically separated…

Mesoscale and Nanoscale Physics · Physics 2023-07-26 Bairen Zhu , Ke Xiao , Siyuan Yang , Kenji Watanabe , Takashi Taniguchi , Xiaodong Cui

We calculate the binding energy, transition energies, oscillator strength, and absorption coefficient of indirect excitons in transition metal dichalcogenide (TMDC) double layers separated by an integer number of hexagonal boron nitride…

Mesoscale and Nanoscale Physics · Physics 2018-09-19 Matthew N. Brunetti , Oleg L. Berman , Roman Ya. Kezerashvili

Single layers of WS2 are direct gap semiconductors with high photoluminescence (PL) yield holding great promise for emerging applications in optoelectronics. The spatial confinement in a 2D monolayer together with the weak dielectric…

Mesoscale and Nanoscale Physics · Physics 2017-05-09 I. Paradisanos , S. Germanis , N. T. Pelekanos , C. Fotakis , E. Kymakis , G. Kioseoglou , E. Stratakis

In this tutorial we introduce the reader to several theoretical methods of determining the exciton wave functions and the corresponding eigenenergies. The methods covered are either analytical, semi-analytical, or numeric. We make explicit…

Mesoscale and Nanoscale Physics · Physics 2022-04-28 M. F. C. Martins Quintela , J. C. G. Henriques , N. M. R. Peres

We report an experimental study documenting the challenge of employing dielectric dilatometry for the study of pressure densification in glass-forming materials. An influence of the dielectric cell geometry on the resulting capacitance of…

Soft Condensed Matter · Physics 2019-02-28 Alejandro Sanz , Jeppe C. Dyre , Kristine Niss

We show how to compute the magnetooptical functions (absorption, reflection, and transmission) when Rydberg Exciton-Polaritons appear, including the effect of the coherence between the electron-hole pair and the electromagnetic field, and…

Mesoscale and Nanoscale Physics · Physics 2017-02-15 Sylwia Zielińska-Raczyńska , David Ziemkiewicz , Gerard Czajkowski

Exciton, trion and biexciton dephasing rates are measured within the inhomogeneous distribution of an InAs quantum dot (QD) ensemble using two-dimensional Fourier-transform spectroscopy. The dephasing rate of each excitonic state is similar…

Mesoscale and Nanoscale Physics · Physics 2014-09-30 G. Moody , R. Singh , H. Li , I. A. Akimov , M. Bayer , D. Reuter , A. D. Wieck , S. T. Cundiff

Temperature influences the performance of two-dimensional materials in optoelectronic devices. Indeed, the optical characterization of these materials is usually realized at room temperature. Nevertheless most {\it ab-initio} studies are…

Mesoscale and Nanoscale Physics · Physics 2016-06-06 Alejandro Molina-Sánchez , Maurizia Palummo , Andrea Marini , Ludger Wirtz

Using a tight-binding Hamiltonian for phosphorene, we have calculated the real part of the polarizability and the corresponding dielectric function, Re$[\epsilon(\textbf{q},\omega)]$, at zero temperature (T = 0) with free carrier density…

Computational Physics · Physics 2018-09-11 Po Hsin Shih , Thi Nga Do , Godfrey Gumbs , Dipendra Dahal

We study the density-density response function of a collection of charged massive Dirac particles and present analytical expressions for the dynamical polarization function in one, two and three dimensions. The polarization function is then…

Mesoscale and Nanoscale Physics · Physics 2017-02-28 Anmol Thakur , Rashi Sachdeva , Amit Agarwal

Two-dimensional (2D) hexagonal boron nitride (BN) nanosheets are excellent dielectric substrate for graphene, molybdenum disulfide and many other 2D nanomaterials based electronic and photonic devices. To optimize the performance of these…

While polarons --- charges bound to a lattice deformation induced by electron-phonon coupling --- are primary photoexcitations at room temperature in bulk metal-halide hybrid organic-inorganic perovskites (HOIP), excitons --- Coulomb-bound…

Materials Science · Physics 2020-04-14 Ajay Ram Srimath Kandada , Carlos Silva

The potential for low-threshold optical nonlinearity has received significant attention in the fields of photonics and conceptual optical neuron networks. Excitons in two-dimensional (2D) semiconductors are particularly promising in this…

Screening in reduced dimensions has strong consequences on the electronic properties in van der Waals semiconductors, impacting the quasiparticle band gap and exciton binding energy. Screening in these materials is typically treated…

Sub-wavelength thick photonic crystal (PhC) slabs coupled to 2D excitonic materials, such as transition metal dichalcogenides (TMDs), are a promising platform for highly tunable, room-temperature, on-chip optoelectronic devices. Unlike…

The optical spectra of CdSe nanocrystals up to 55 A in diameter are analyzed in a wide range of energies from the fine structure of the low-energy excitations to the so-called high-energy transitions. We apply a symmetry-based method in two…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 J. Perez-Conde , A. K. Bhattacharjee

Dielectric responses of a multi-component plasma are investigated at finite temperature considering the case of optically generated carriers in a wurtzite GaN. The effective dielectric function and polarizability functions $\Pi_c…

Strongly Correlated Electrons · Physics 2014-10-21 Kyung-Soo Yi , Hye-Jung Kim

We have performed first-principles calculations to study optical absorption spectra of doped graphene with many-electron effects included. Both self-energy corrections and electron-hole interactions are reduced due to the enhanced screening…

Mesoscale and Nanoscale Physics · Physics 2011-09-09 Li Yang