ELFT HÍRADÓ

[Miklós Werner <wernermiklos AT gmail.com>]

A BME-MTA Egzotikus Kvantumfázisok csoport következő szemináriuma:

Wataru Izumida (Tohoku University, Sendai, Japán)
Zero energy edge states and topology in carbon nanotubes

2017. augusztus 29., kedd, 14:15
BME Elméleti Fizika Tanszék szemináriumi szobája (F épület, 3. lépcsőház,
magasföldszint)

Kivonat:
"In this talk, I will present our recent studies on zero energy edge
 states in finite-length carbon nanotubes from topological viewpoint.

 An effective one-dimensional (1D) lattice model for a single-wall
 carbon nanotube (SWNT) is introduced to analyze the quantum system
 with boundary [1].  Open-ended SWNTs commonly host edge states whose
 energies lie in the bulk band gap.  By analyzing the 1D lattice model
 a bulk-edge correspondence is proven, which shows that the number of
 edge states and a winding number topological invariant defined in the
 corresponding bulk system are identical [2].  Manipulation of the edge
 states by a magnetic field is suggested in terms of the topological
 phase transition [3].

 We extend these studies to investigate the nature of edge states which
 arise when the SWNT is proximity coupled to a superconductor [4].  The
 zero energy edge states emerge as a combined effect of
 curvature-induced Dirac point shift and strong superconducting
 coupling between nearest-neighbor sites.  A 1D continuum model reveals
 the topological origin of the zero energy edge states.

 [1] W. Izumida, R. Okuyama, R. Saito, Phys. Rev. B 91, 235442 (2015)
 [2] W. Izumida, R. Okuyama, A. Yamakage, R. Saito, Phys. Rev. B 93, 195442
(2016)
 [3] R. Okuyama, W. Izumida, M. Eto, J. Phys. Soc. Jpn. 86, 013702 (2017)
 [4] W. Izumida, L. Milz, M. Marganska, M. Grifoni, arXiv:1707.02934"

Minden érdeklődőt szeretettel várunk.

A szemináriumsorozat további programja:
http://exotic.phy.bme.hu/seminars.html

Üdvözlettel,
Werner Miklós Antal