ELFT HÍRADÓ

[Andras Palyi <andraspalyi AT caesar.elte.hu>]

Az ELTE Nanofizika Szeminarium jovo hetfoi eloadasa:


Matthias Droth (Universitat Konstanz, Nemetorszag):
Piezoelectricity in planar boron nitride via a geometric phase

Kivonat: 
“Due to their low surface mass density, two-dimensional materials with a 
strong piezoelectric response are interesting for nanoelectromechanical 
systems with high force sensitivity. In contrast to graphene, the two 
sublattices in two-dimensional hexagonal boron nitride (hBN) are occupied by 
different types of atoms, which allows for piezoelectricity. Recently, the 
piezoelectric tensor of extended hBN has been calculated via density 
functional theory (DFT) [1]. While an analytical description of 
piezoelectricity does exist for hBN nanotubes [2], this is, to our knowledge, 
not the case for two-dimensional hBN. We set up a Hamiltonian that involves 
the strain-induced pseudomagnetic field [3] and derive the piezoelectric 
tensor using the modern theory of polarization. Our findings are in exact 
agreement with symmetry arguments and give an analytical explanation for the 
piezoelectric electron-phonon coupling in planar hBN. We also provide an 
estimation of the coupling strength and a piezoelectric response similar to 
reported DFT results.

References
[1] Karel-Alexander Duerloo, Mitchell T. Ong, and Evan J. Reed, J. Phys. 
Chem. 3, 2871
(2012).
[2] E. J. Mele and Petr Král, Phys. Rev. Lett. 88, 056803 (2002).
[3] Hidekatsu Suzuura and Tsuneya Ando, Phys. Rev. B 65, 235412 (2002)."

Idopont: 2015. marcius 23. hetfo, 10:15
Helyszin: ELTE Eszaki Tomb, 5.128-as terem (1117 Budapest, Pazmany Peter 
setany 1/A)


Minden erdeklodot szivesen latunk.

A szeminarium tovabbi programja: http://wigner.elte.hu/science/?q=seminar

Udvozlettel,
Palyi Andras