title: Carrier density independent scattering rate in SrTiO3-based electron liquids.
abstract: We examine the carrier density dependence of the scattering rate in two- and three-dimensional electron liquids in SrTiO3 in the regime where it scales with T(n) (T is the temperature and n ≤ 2) in the cases when it is varied by electrostatic control and chemical doping, respectively. It is shown that the scattering rate is independent of the carrier density. This is contrary to the expectations from Landau Fermi liquid theory, where the scattering rate scales inversely with the Fermi energy (EF). We discuss that the behavior is very similar to systems traditionally identified as non-Fermi liquids (n < 2). This includes the cuprates and other transition metal oxide perovskites, where strikingly similar density-independent scattering rates have been observed. The results indicate that the applicability of Fermi liquid theory should be questioned for a much broader range of correlated materials and point to the need for a unified theory.
authors: Materials Department, University of California, Santa Barbara, CA 93106-5050, USA.
authors: Evgeny
authors: E
authors: Mikheev
authors: Materials Department, University of California, Santa Barbara, CA 93106-5050, USA.
authors: Santosh
authors: S
authors: Raghavan
authors: Materials Department, University of California, Santa Barbara, CA 93106-5050, USA.
authors: Jack Y
authors: JY
authors: Zhang
authors: Materials Department, University of California, Santa Barbara, CA 93106-5050, USA.
authors: Patrick B
authors: PB
authors: Marshall
authors: Materials Department, University of California, Santa Barbara, CA 93106-5050, USA.
authors: Adam P
authors: AP
authors: Kajdos
authors: Kavli Institute for Theoretical Physics, University of California, Santa Barbara, California 93106-4030, USA.
authors: Leon
authors: L
authors: Balents
authors: Materials Department, University of California, Santa Barbara, CA 93106-5050, USA.
authors: Susanne
authors: S
authors: Stemmer