The authors report on the terahertz time-domain spectroscopy of single-walled carbon nanotubes (SWCNTs) dispersed in a polymer film in a broad frequency range from 0.2to20THz. The complex dielectric function of the composite film is obtained without using Kramers-Kronig analysis, from which the dielectric function of SWCNTs is extracted by using the effective medium theory. The real part of the dielectric function exhibits very large values at low frequency below 2THz. The conductivity spectrum shows a peak around 3THz. The spectral behavior is consistent with overdamped Lorentz oscillator model, indicating the response of curvature-induced small-gap SWCNTs.

1.
R.
Saito
,
G.
Dresselhaus
, and
M. S.
Dresselhaus
,
Physical Properties of Carbon Nanotubes
(
Imperial College Press
,
London
,
1998
), Chap. 4, pp.
59
72
.
2.
N.
Hamada
,
S.
Sawada
, and
A.
Oshiyama
,
Phys. Rev. Lett.
68
,
1579
(
1992
).
3.
C. L.
Kane
and
E. J.
Mele
,
Phys. Rev. Lett.
78
,
1932
(
1997
).
4.
A.
Kleiner
and
S.
Eggert
,
Phys. Rev. B
63
,
073408
(
2001
).
5.
Small gaps caused by strong hybridization of σ*-π* states have also been discussed in
X.
Blase
,
L. X.
Benedict
,
E. L.
Shirley
, and
S. G.
Louie
,
Phys. Rev. Lett.
72
,
1878
(
1994
).
6.
C.
Zhou
,
K.
Jing
, and
H.
Dai
,
Phys. Rev. Lett.
84
,
5604
(
2000
).
7.
M.
Ouyang
,
J.-L.
Hhang
,
C. L.
Cheung
, and
C. M.
Lieber
,
Science
292
,
702
(
2001
).
8.
A.
Ugawa
,
A. G.
Rinzler
, and
D. B.
Tanner
,
Phys. Rev. B
60
,
R11305
(
1999
).
9.
M. E.
Itkis
,
S.
Niyogi
,
M. E.
Meng
,
M. A.
Hamon
,
H.
Hu
, and
R. C.
Haddon
,
Nano Lett.
2
,
155
(
2002
).
10.
N.
Akima
,
Y.
Iwasa
,
S.
Brown
,
A. M.
Barbour
,
J.
Cao
,
J. L.
Musfeldt
,
H.
Matsui
,
N.
Toyota
,
M.
Shiraishi
,
H.
Shimoda
, and
O.
Zhou
,
Adv. Mater. (Weinheim, Ger.)
18
,
1166
(
2006
).
11.
T.-I.
Jeon
,
K.-J.
Kim
,
C.
Kang
,
I. H.
Maeng
,
J.-H.
Son
,
K. H.
An
,
J. Y.
Lee
, and
Y. H.
Lee
,
J. Appl. Phys.
95
,
5736
(
2004
).
12.
A.
Rice
,
Y.
Jin
,
X. F.
Ma
,
X.-C.
Zhang
,
D.
Bliss
,
J.
Larkin
, and
M.
Alexander
,
Appl. Phys. Lett.
64
,
1324
(
1994
).
13.
D.
Grischkowsky
,
S.
Keiding
,
M.
van Exter
, and
Ch.
Fattinger
,
J. Opt. Soc. Am. B
7
,
2006
(
1990
).
14.
S.
Kono
,
M.
Tani
, and
K.
Sakai
,
Appl. Phys. Lett.
79
,
898
(
2001
).
15.
N.
Minami
,
Y.
Kim
,
K.
Miyashita
,
S.
Kazaoui
, and
B.
Nalini
,
Appl. Phys. Lett.
88
,
093123
(
2006
).
16.
G. L.
Carr
,
S.
Perkowitz
, and
D. B.
Tanner
, in
Infrared and Millimeter Waves
, edited by
K. J.
Button
(
Academic
,
New York
,
1985
), Vol.
13
, Chap. 6, pp.
171
263
.
17.
T. W.
Noh
,
P. H.
Song
, and
A. J.
Sievers
,
Phys. Rev. B
44
,
5459
(
1991
).
18.
L. X.
Benedict
,
S. G.
Louie
, and
M. L.
Cohen
,
Phys. Rev. B
52
,
8541
(
1995
).
19.
B.
Kozinsky
and
N.
Marzari
,
Phys. Rev. Lett.
96
,
166801
(
2006
).
You do not currently have access to this content.