title: Evidence of weak localization in quantum interference effects observed in epitaxial La0.7Sr0.3MnO3 ultrathin films.
abstract: Quantum interference effects (QIEs) dominate the appearance of low-temperature resistivity minimum in colossal magnetoresistance manganites. The T(1/2) dependent resistivity under high magnetic field has been evidenced as electron-electron (e-e) interaction. However, the evidence of the other source of QIEs, weak localization (WL), still remains insufficient in manganites. Here we report on the direct experimental evidence of WL in QIEs observed in the single-crystal La0.7Sr0.3MnO3 (LSMO) ultrathin films deposited by laser molecular beam epitaxy. The sharp cusps around zero magnetic field in magnetoresistance measurements is unambiguously observed, which corresponds to the WL effect. This convincingly leads to the solid conclusion that the resistivity minima at low temperatures in single-crystal manganites are attributed to both the e-e interaction and the WL effect. Moreover, the temperature-dependent phase-coherence length corroborates the WL effect of LSMO ultrathin films is within a two-dimensional localization theory.
authors.affiliation: National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Niu
authors.affiliation: National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Gao
authors.affiliation: National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Xuefeng
authors.initials: X
authors.lastname: Wang
authors.affiliation: National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and Department of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Fengqi
authors.initials: F
authors.lastname: Song
authors.affiliation: National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and Department of Physics, Nanjing University, Nanjing 210093, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Du
authors.affiliation: National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Xinran
authors.initials: X
authors.lastname: Wang
authors.affiliation: National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Yongbing
authors.initials: Y
authors.lastname: Xu
authors.affiliation: National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, and School of Electronic Science and Engineering, Nanjing University, Nanjing 210093, China.
authors.forename: Rong
authors.initials: R
authors.lastname: Zhang