title: Optical study of the free-carrier response of LaTiO3/SrTiO3 superlattices.
abstract: 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.
authors.affiliation: ReCOE & FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea.
authors.forename: S S A
authors.initials: SS
authors.lastname: Seo
authors.forename: W S
authors.initials: WS
authors.lastname: Choi
authors.forename: H N
authors.initials: HN
authors.lastname: Lee
authors.forename: L
authors.initials: L
authors.lastname: Yu
authors.forename: K W
authors.initials: KW
authors.lastname: Kim
authors.forename: C
authors.initials: C
authors.lastname: Bernhard
authors.forename: T W
authors.initials: TW
authors.lastname: Noh