Author(s): M. Grüning and C. Attaccalite
We study second harmonic generation in h-BN and MoS2 monolayers using an ab initio approach based on many-body theory. We show that electron-hole interaction doubles the signal intensity at the excitonic resonances with respect to the contribution from independent electronic transitions. This implie...
[Phys. Rev. B 89, 081102] Published Mon Feb 03, 2014
Author(s): Yongqing Cai, Jinghua Lan, Gang Zhang, and Yong-Wei Zhang
The anharmonic behavior of phonons and intrinsic thermal conductivity associated with the umklapp scattering in monolayer MoS2 sheet are investigated via first-principles calculations within the framework of density functional perturbation theory. In contrast to the negative Grüneissen parameter (γ)...
[Phys. Rev. B 89, 035438] Published Fri Jan 31, 2014
Author(s): Y. Benny, R. Presman, Y. Kodriano, E. Poem, D. Gershoni, T. A. Truong, and P. M. Petroff
We use temporally resolved intensity cross-correlation measurements to identify the biexciton-exciton radiative cascades in a negatively charged QD. The polarization sensitive correlation measurements show unambiguously that the excited two-electron triplet states relax nonradiatively to their singl...
[Phys. Rev. B 89, 035316] Published Fri Jan 31, 2014
Author(s): Jeongsu Lee, Karel Výborný, Jong E. Han, and Igor Žutić
Conventional understanding implies that the ground state of a nonmagnetic quantum mechanical system should be nodeless. While this notion also provides a valuable guidance in understanding the ordering of energy levels in semiconductor nanostructures, there are reports that nodal ground states for h...
[Phys. Rev. B 89, 045315] Published Fri Jan 31, 2014
Author(s): Charles A. Foell, Keith A. Abel, Frank C. J. M. van Veggel, and Jeff F. Young
A kinetic model is derived and used to analyze recently published works and new data on the temperature dependence of the spectrally integrated photoluminescence (PL) from thick-film formulations of PbSe colloidal quantum dots (QDs), with particular attention to the effects of air exposure. The mode...
[Phys. Rev. B 89, 045139] Published Wed Jan 29, 2014
Author(s): P. A. Labud, A. Ludwig, A. D. Wieck, G. Bester, and D. Reuter
We present capacitance-voltage spectra for the conduction band states of InAs quantum dots obtained under continuous illumination. The illumination leads to the appearance of additional charging peaks that we attribute to the charging of electrons into quantum dots containing a variable number of il...
[Phys. Rev. Lett. 112, 046803] Published Wed Jan 29, 2014
Author(s): D. Lagarde, L. Bouet, X. Marie, C. R. Zhu, B. L. Liu, T. Amand, P. H. Tan, and B. Urbaszek
In monolayer MoS2, optical transitions across the direct band gap are governed by chiral selection rules, allowing optical valley initialization. In time-resolved photoluminescence (PL) experiments, we find that both the polarization and emission dynamics do not change from 4 to 300 K within our tim...
[Phys. Rev. Lett. 112, 047401] Published Mon Jan 27, 2014
Author(s): Patryk Kusch, Eugen Grelich, Claudio Somaschini, Esperanza Luna, Manfred Ramsteiner, Lutz Geelhaar, Henning Riechert, and Stephanie Reich
We used spatially resolved photoluminescence (PL) and resonant Raman spectroscopy to study the electronic structure of single GaAs nanowires (NWs) consisting of zinc-blende (ZB) and wurtzite (WZ) segments. For narrow ZB segments and stacking faults the energy range of the observed PL peak positions ...
[Phys. Rev. B 89, 045310] Published Mon Jan 27, 2014
Steam condenses onto a hydrophobic grafted copoly mer film to form discrete condensate drops, leading to a seven-fold increase in heat transfer coefficient over a typical hydrophilic metal surface. Most hydrophobic modifiers quickly degrade in the presence of steam, but this covalently bonded crosslinked fluoropolymer withstands an accelerated endurance test with no change in performance, as described by Kripa K. Varanasi, Karen K. Gleason and co-workers on page 418.
Author(s): S. H. R. de Sena, J. M. Pereira, Jr., F. M. Peeters, and G. A. Farias
We calculate the spectrum of states that are localized at the interface between two regions of opposite bias in trilayer graphene (TLG). These potential profiles, also known as potential kinks, have been predicted to support two different branches of localized states for the case of bilayer graphene...
[Phys. Rev. B 89, 035420] Published Thu Jan 16, 2014
Physics: Why penguins do the wave
Nature 505, 7483 (2014). doi:10.1038/505265e
Highly read on iopscience.iop.org 9 Dec–8 JanPhysicists have explained how waves of coordinated motion sweep through huddles of male emperor penguins (Aptenodytes forsteri; pictured) as they try to keep warm while incubating eggs in the Antarctic.Daniel Zitterbart and Richard Gerum
Author(s): D. Canneson, L. Biadala, S. Buil, X. Quélin, C. Javaux, B. Dubertret, and J.-P. Hermier
The fluorescence of single colloidal thick-shell CdSe/CdS nanocrystals (NCs), at cryogenic temperature (4 K) and room temperature (RT), is studied using the intensity autocorrelation function (ACF) and lifetime measurements. The radiative and Auger decay rates corresponding to the desexcitation of t...
[Phys. Rev. B 89, 035303] Published Thu Jan 09, 2014
