[1/27] The 8th WPI-AIMR Joint Seminar in FY2016

01/23/2017

The 8th WPI-AIMR Joint Seminar in FY2016

Title

Nanoscale edge effects on graphene and related materials

Speaker

Prof. Katsunori Wakabayashi
(School of Science and Technology, Kwansei Gakuin University)

Date

January 27 (Fri.), 2016 14:30-15:30

Venue

Seminar Room, 2nd floor, WPI-AIMR Main Bldg.

Abstract

Electronic states of graphene are well described as massless Dirac fermion. The presence of edges, however, makes strong implications for the spectrum of the electrons. As first, I will briefly give overview of edge and nanoscale effects on magnetic and transport properties of graphene nanostructures [1]. It is known that edge states can induce spin-polarization with ferromagnetic correlation along the zigzag edges. Our recent many-body analysis shows that the system becomes metallic and magnetic ground states by hole doping [2]. Graphene nanoribbons can possess a perfectly conducting channel when the intervalley scattering is sufficiently suppressed. The mechanism is owing to the breaking of pseudo-time reversal symmetry [3]. We will discuss the possible formation mechanism of quasi-bound states in graphene quantum point contacts [4]. In further, we also discuss our recent work on electronic properties of carbon nanotubes under circularly polarized light, which show the valley polarization of electrons [5].


  • [1] K. Wakabayashi, et.al., Sci. Technol. Adv. Mat. 11, 054504 (2010).
  • [2] S. Dutta, and K. Wakabayashi, Sci. Rep. 2, 519 (2012)
  • [3] K. Wakabayashi, et.al., Phys. Rev. Lett. 99, 036601 (2007); CARBON 47, 124 (2009)
  • [4] H.-Y. Deng and K. Wakabayashi, Phys. Rev. B90, 115413 (2014); Phys. Rev. B90, 045402 (2014); Phys. Rev. B89, 045423 (2014).
  • [5]. Liu, Y. Nakajima, K. Wakabayashi, Appl. Phys. Exp. 9, 085101 (2016).

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Contact

International Affairs Center (IAC), AIMR

Address : 2-1-1, Katahira, Aoba-ku, Sendai, 980-8577
TEL : +81-22-217-5971
E-MAIL : iac@grp.tohoku.ac.jp