Ergodic vs diffusive decoherence in mesoscopic devices

Abstract

We report on the measurement of phase coherence length in a high mobility two-dimensional electron gas patterned in two different geometries, a wire and a ring. The phase coherence length is extracted both from the weak localization correction in long wires and from the amplitude of the Aharonov-Bohm oscillations in a single ring, in a low temperature regime when decoherence is dominated by electronic interactions. We show that these two measurements lead to different phase coherence lengths, namely $L_{\Phi }^{\mathrm{wire}}\propto T^{-1/3}$ and $L_{\Phi }^{\mathrm{ring}}\propto T^{-1/2}$. This difference reflects the fact that the electrons winding around the ring necessarily explore the whole sample (ergodic trajectories), while in a long wire the electrons lose their phase coherence before reaching the edges of the sample (diffusive regime).

LaTeX, 5 pages, 4 pdf figures ; v2: revised version

References in corpus (18)

• Dephasing of Electrons in Mesoscopic Metal Wires
• Mesoscopic decoherence in Aharonov-Bohm rings
• Inelastic Electron Lifetime in Disordered Mesoscopic Systems
• Interaction corrections at intermediate temperatures: dephasing time
• Inelastic Scattering Time for Conductance Fluctuations
• Interaction-induced dephasing of Aharonov-Bohm oscillations
• Magnetic field asymmetry of mesocopic dc rectification in Aharonov Bohm rings
• Quantum Coherence at Low Temperatures in Mesoscopic Systems: Effect of Disorder
• Probe-Configuration-Dependent Decoherence in an Aharonov-Bohm Ring
• Dephasing due to electron-electron interaction in a diffusive ring
• Electron coherence at low temperatures: The role of magnetic impurities
• Effect of Disorder on the Quantum Coherence in Mesoscopic Wires
• Geometrical dependence of decoherence by electronic interactions in a GaAs/GaAlAs square network
• Quantum oscillations and decoherence due to electron-electron interaction in metallic networks and hollow cylinders
• Dimensional crossover in quantum networks: from macroscopic to mesoscopic Physics
• Thermal noise and dephasing due to electron interactions in non-trivial geometries
• Dimensional Crossover of the Dephasing Time in Disordered Mesoscopic Rings
• Effect of connecting wires on the decoherence due to electron-electron interaction in a metallic ring

Cited by in corpus (6)

• Return to the Origin as a Probe of Atomic Phase Coherence
• Coherent multiple scattering of out-of-equilibrium interacting Bose gases
• Coherence-enhanced, phase-dependent dissipation in long SNS Josephson junctions: revealing Andreev Bound States dynamics
• Non-linear conductance in mesoscopic weakly disordered wires -- Interaction and magnetic field asymmetry
• Four-terminal resistances in mesoscopic networks of metallic wires: Weak localisation and correlations
• Field effect induced mesoscopic devices in depleted two dimensional electron systems