title: Kosterlitz-Thouless-type transition in a charge ordered state of the layered organic conductor α-(BEDT-TTF)2I3.
abstract: The current-voltage characteristics in the charge order state of the two-dimensional organic conductor α-(BEDT-TTF)(2)I(3) exhibit power law behavior at low temperatures. The power law is understood in terms of the electric-field-dependent potential between electrons and holes, which are thermally excited from the charge order state. The power law exponent steeply changes from 1 to 3 in the range from 30 to 45 K with decreasing temperature, thereby suggesting the occurrence of a Kosterlitz-Thouless-type transition; many (few) unbound electron-hole pairs are thermally excited above (below) the transition. The effects of the finite size and interlayer coupling on the power law behavior are discussed.
authors.affiliation: National Institute for Materials Science, Tsukuba, Ibaraki 305-0003, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Uji
authors.forename: K
authors.initials: K
authors.lastname: Kodama
authors.forename: K
authors.initials: K
authors.lastname: Sugii
authors.forename: Y
authors.initials: Y
authors.lastname: Takahide
authors.forename: T
authors.initials: T
authors.lastname: Terashima
authors.forename: N
authors.initials: N
authors.lastname: Kurita
authors.forename: S
authors.initials: S
authors.lastname: Tsuchiya
authors.forename: M
authors.initials: M
authors.lastname: Kohno
authors.forename: M
authors.initials: M
authors.lastname: Kimata
authors.forename: K
authors.initials: K
authors.lastname: Yamamoto
authors.forename: K
authors.initials: K
authors.lastname: Yakushi