Skip to content.

TUD

search  |  internal  |  deutsch
Personal tools
TU Dresden » Faculty of Mechanical Science and Engineering » Institute for Materials Science » Chair of Materials Science and Nanotechnology



Friday, 30 September 2005
(at 13:45 in room Phy 4.1.13)
Add to your Google Calendar


Spectroscopy of carbon nanotubes in ultrahigh magnetic fields

Junichiro Kono

Department of Electrical and Computer Engineering
Rice University
  USA  






Single-walled carbon nanotubes (SWNTs) provide a unique playground for the exploration of novel physical phenomena at high magnetic fields. For example, while a magnetic field applied parallel to the tube axis is predicted to periodically modify the band structure through the Aharonov-Bohm phase [1], a perpendicular field is predicted to induce lattice instability and distortion [2]. They are expected to possess highly anisotropic magnetic susceptibilities [3], which allow them to align with an external magnetic field easily. Furthermore, the degeneracy between the `right-handed' and `left-handed' electrons can be lifted by breaking the time-reversal symmetry by a parallel magnetic field, which is expected to `brighten' some of the Coulomb-induced dark exciton states.

Here we present results of our recent high-field magneto-optical experiments [4], which clearly demonstrate the influence of the magnetic flux φ threading the SWNTs on their electronic structure. Magneto-absorption and magneto-photoluminescence spectroscopies in high DC and pulsed magnetic fields revealed field-induced optical anisotropy as well as peak shifts and splittings. The amounts of shifts and splittings were found to be determined by the value of φ/φ0 (where φ0 is the magnetic flux quantum) in a predictable way. The band gap of semiconducting SWNTs with 1 nm diameter was shown to shrink with magnetic field at ~ 1 meV/T. Furthermore, we will show time-resolved magneto-optical transmission data, which indicates that the nanotubes can dynamically align in response to μs-paperref time-scale pulsed magnetic fields.

[1]H. Ajiki and T. Ando, J. Phys. Soc. Jpn. 62, 1255 (1993).
[2]N. A. Viet, H. Ajiki, and T. Ando, J. Phys. Soc. Jpn. 63, 3036 (1993).
[3]H. Ajiki and T. Ando, J. Phys. Soc. Jpn. 63, 4267 (1994); ibid. 64, 4382 (1994);
J. P. Lu, Phys. Rev. Lett. 74, 1123 (1994).
[4]S. Zaric, G. N. Ostojic, J. Kono, J. Shaver, V. C. Moore, M. S. Strano, R. H. Hauge, R. E. Smalley, and X. Wei, Science 304, 1129 (2004);
S. Zaric, G. N. Ostojic, J. Kono, J. Shaver, V. C. Moore, R. H. Hauge, R. E. Smalley, and X. Wei, Nano Lett. 4, 2219 (2004).

Brief Bio:

1990 B.S. applied physics University of Tokyo (Japan)

1992 M.S. applied physics, University of Tokyo (Japan)

1995 Ph.D. Physics, State University of New York at Buffalo (USA)

1995-2000 postocs at University of California at Santa Barbara (USA), Stanford University (USA)

2000-2005 Assistant Professor, Department of Electrical and Computer Engineering, Rice University, Houston, Texas

since 2005 Associate Professor, Department of Electrical and Computer Engineering, Rice University, Houston, Texas



slides (pdf)

slides (ppt)

related paper (pdf)

related paper (html)

Invited by G. Cuniberti (MC seminar)

last modified: 2018.10.24 Mi
author: webadmin