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Direct measurement of the phase coherence length in a GaAs/GaAlAs square network

Meydi Ferrier·Lionel Angers·Sophie Gueron·Helene Bouchiat·Christophe Texier·Gilles Montambaux·Dominique Mailly·Alistair C. H. Rowe
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Abstract

The low temperature magnetoconductance of a large array of quantum coherentloops exhibits Altshuler-Aronov-Spivak oscillations which periodicitycorresponds to 1/2 flux quantum per loop.We show that the measurement of the harmonics content in a square networkprovides an accurate way to determine the electron phase coherence length$L\_ϕ$ in units of the lattice length without any adjustableparameters.We use this method to determine $L\_ϕ$ in a network realised from a 2Delectron gas (2DEG) in a GaAS/GaAlAs heterojunction. The temperaturedependence follows a power law $T^{-1/3}$ from 1.3 K to 25 mK with nosaturation, as expected for 1D diffusive electronic motion andelectron-electron scattering as the main decoherence mechanism.

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Meydi Ferrier, Lionel Angers, Sophie Gueron, Helene Bouchiat, Christophe Texier, Gilles Montambaux, Dominique Mailly, Alistair C. H. Rowe. 2005-02-15. Direct measurement of the phase coherence length in a GaAs/GaAlAs square network. https://doi.org/10.1103/physrevlett.93.246804

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