Optical study of the free-carrier response of LaTiO3/SrTiO3 superlattices.
We used infrared spectroscopic ellipsometry to investigate the electronic properties of LaTiO_{3}/SrTiO_{3} superlattices (SLs). Our results indicated that, independent of the SL periodicity and individual layer thickness, the SLs exhibited a Drude metallic response with sheet carrier density per interface approximately 3x10;{14} cm;{-2}. This is probably due to the leakage of d electrons at interfaces from the Mott insulator LaTiO3 to the band insulator SrTiO3. We observed a carrier relaxation time approximately 35 fs and mobility approximately 35 cm;{2} V-1 s;{-1} at 10 K, and an unusual temperature dependence of carrier density that was attributed to the dielectric screening of quantum paraelectric SrTiO3.
Seo
S S A
SS
ReCOE & FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea.
Choi
W S
WS
Lee
H N
HN
Yu
L
L
Kim
K W
KW
Bernhard
C
C
Noh
T W
TW