Zobrazeno 1 - 10
of 77
pro vyhledávání: '"Psiachos, D."'
Autor:
Psiachos, D., Sigalas, M. M.
Publikováno v:
Phys. Rev. Applied 15, 014022 (2021)
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 cylinders periodi
Externí odkaz:
http://arxiv.org/abs/2008.11597
Autor:
Psiachos, D., Sigalas, M. M.
Publikováno v:
Phys. Rev. B 99, 184110 (2019)
We investigate elastic-wave propagation in a spatially-dispersive multilayered, totally passive metamaterial system. At oblique incidence a longitudinal (acoustic) wave can convert to transverse in the solid material comprising the layers, but when t
Externí odkaz:
http://arxiv.org/abs/1901.02340
Autor:
Psiachos, D., Sigalas, M. M.
Publikováno v:
Journal of Applied Physics v.123 p.245109 (2018)
Using transfer-matrix methods, we investigate the response of a multilayered metamaterial system containing defects to an incident acoustic plane wave at normal or oblique incidence. The transmission response is composed of pass-bands with oscillator
Externí odkaz:
http://arxiv.org/abs/1710.09816
Autor:
Psiachos, D.
In a recent paper, the authors propose to separately calculate the volumetric and chemical contributions to the elastic stiffness coefficients of systems containing solutes, as it is "computationally more efficient". We show that this is not the case
Externí odkaz:
http://arxiv.org/abs/1708.08091
Autor:
Psiachos, D.
This comment regards a central aspect of the referred-to paper, the issue of convergence of the large coordination-number expansion. Perturbation expansions of expressions containing a large number of parameters are generally invalid due to the non-a
Externí odkaz:
http://arxiv.org/abs/1604.07158
Autor:
Psiachos, D.
Publikováno v:
Chem. Phys. Lett. v. 662 p. 201-207 (2016)
We investigate time-dependent electron transfer (ET) in benchmark donor-bridge-acceptor systems. For the small bridge sizes studied, we obtain results far different from the perturbation theory which underlies scattering-based approaches, notably a l
Externí odkaz:
http://arxiv.org/abs/1603.07715
Autor:
Psiachos, D.
Publikováno v:
Annals of Physics, v. 360 p. 33-43 (2015)
We discuss the well-known three-center cation-anion-cation model for superexchange in insulating transition-metal compounds using limiting expansions for the Anderson-Hubbard model. We find that due to the three interfering energy scales in the model
Externí odkaz:
http://arxiv.org/abs/1407.3665
Autor:
Psiachos, D.
Publikováno v:
Chemical Physics, vol. 436/437, p. 8 (2014)
We examine, using mixed classical-quantum electron-ion dynamics, electron transfer in a donor-acceptor-like molecular junction system based on polyacetylene. We identify two qualitatively-different transfer regimes: hopping and tunnelling. We discuss
Externí odkaz:
http://arxiv.org/abs/1303.1318
Autor:
Psiachos, D.
Publikováno v:
Modelling Simul. Mater. Sci. Eng. 20 (2012) 035011
The calculated effects of interstitial hydrogen on the elastic properties of alpha-iron from our earlier work are used to describe the H interactions with homogeneous strain fields using ab initio methods. In particular we calculate the H solublility
Externí odkaz:
http://arxiv.org/abs/1105.5758
Publikováno v:
Acta Materialia v 59, iss 11, p 4255 (2011)
The effect of hydrostatic strain and of interstitial hydrogen on the elastic properties of $\alpha$-iron is investigated using \textit{ab initio} density-functional theory calculations. We find that the cubic elastic constants and the polycrystalline
Externí odkaz:
http://arxiv.org/abs/1102.0187