title: Direct measurement of the phase-coherence length in a GaAs/GaAlAs square network.
abstract: The low temperature magnetoconductance of a large array of quantum coherent loops exhibits Altshuler-Aronov-Spivak oscillations with a periodicity corresponding to 1/2 flux quantum per loop. We show that the measurement of the harmonics content provides an accurate way to determine the electron phase-coherence length L(phi) in units of the lattice length with no adjustable parameters. We use this method to determine L(phi) in a square network realized from a 2D electron gas in a GaAs/GaAlAs heterojunction, with only a few conducting channels. The temperature dependence follows a power law T(-1/3) from 1.3 K to 25 mK with no saturation, as expected for 1D diffusive electronic motion and electron-electron scattering as the main decoherence mechanism.
authors.affiliation: Laboratoire de Physique des Solides, Associé au CNRS, Université Paris-Sud, 91405 Orsay, France.
authors.forename: M
authors.initials: M
authors.lastname: Ferrier
authors.forename: L
authors.initials: L
authors.lastname: Angers
authors.forename: A C H
authors.initials: AC
authors.lastname: Rowe
authors.forename: S
authors.initials: S
authors.lastname: Guéron
authors.forename: H
authors.initials: H
authors.lastname: Bouchiat
authors.forename: C
authors.initials: C
authors.lastname: Texier
authors.forename: G
authors.initials: G
authors.lastname: Montambaux
authors.forename: D
authors.initials: D
authors.lastname: Mailly