Berlin 2015 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 103: Transport: Poster Session

TT 103.20: Poster

Donnerstag, 19. März 2015, 15:00–18:00, Poster B

Nanomechanics and strain engineering in 2d materials — •Alexander Croy¹, Daniel Midtvedt¹, and Caio H. Lewenkopf² — ¹Max-Planck-Institute for the Physics of Complex Systems, Dresden, Germany — ²Universidade Federal Fluminense, Niterói, Brazil

We investigate the electromechanical coupling in two-dimensional materials. To this end we put forward a systematic approach to relate the macroscopic strain tensor to microscopic atomic displacements. This strain-displacement relation depends non-trivially on the lattice structure and the parameters of the force field model. Implications for nanomechanical properties and electromechanical coupling in two-dimensional materials are discussed. Using graphene as a study case, we combine a tight binding and a valence force-field model to calculate the electronic (DOS, band energy) and mechanical properties (elastic modulus, Poisson ratio) of graphene nanoribbons under strain. We then compare those calculations with results obtained from the Dirac equation coupled to continuum mechanics. In this long wave-limit effective theory we find a renormalization correction to the strain-induced pseudo-magnetic fields which is connected to the strain-displacement relation.