Phase coherent transport in a side-gated mesoscopic graphite wire

TL;DR

This study explores phase coherent transport in a mesoscopic graphite wire, revealing that phase coherence length exceeds wire width and increases with conductivity, primarily due to electron-electron interactions at low temperatures.

Contribution

It demonstrates the electric field control of conductance and characterizes phase coherence in a mesoscopic graphite wire, highlighting the dominance of electron-electron interactions in dephasing.

Findings

Phase coherence length exceeds wire width at low densities.

Coherence length increases linearly with conductivity.

Dephasing mainly caused by electron-electron interactions at 1.7 K.

Abstract

We investigate the magnetotransport properties of a thin graphite wire resting on a silicon oxide substrate. The electric field effect is demonstrated with back and side gate electrodes. We study the conductance fluctuations as a function of gate voltage, magnetic field and temperature. The phase coherence length extracted from weak localization is larger than the wire width even at the lowest carrier densities making the system effectively one-dimensional. We find that the phase coherence length increases linearly with the conductivity suggesting that at 1.7 K dephasing originates mainly from electron-electron interactions.