Correlated electron transport in one-dimensional mesoscopic conductors

Mesoscopic systems have emerged as a result of advanced microfabrication processing. These systems provide a new playground where tailor-made structures are available. This enables the study of quantum phenomena due to dimensional confinement and manipulation of system geometries. Two specific systems are investigated in this dissertation: single-walled carbon nanotubes and quantum point contacts in a two-dimensional electron gas.; Single-walled carbon nanotubes (SWNTs) provide a testbed to explore unique quantum behaviors of one-dimensional (1D) systems. Unlike two- or three-dimensional counterparts, in which the Coulomb screening justifies an independent single particle picture, the ground-state properties and system dynamics of 1D conductors are deeply rooted in more complicated electron-electron interactions. One manifestation of the 1D features is in electrical transport properties. Recently, the electrical contacts between tubes and metal electrodes have been improved, allowing us to observe quantum interference in ballistic SWNTs analogous to intensity fringes in Fabry-Perot cavities. Electron transport properties of well-contacted SWNTs via measurements of differential conductance and low-frequency shot noise are focused. Experimental results exhibit strong correlations among conducting channels. The interpretation of experimental observations within the Tomonaga-Luttinger liquid (TLL) theory is discussed, which provides qualitative and quantitative agreements with experiments. Especially, the characteristic TLL parameter inferred from the differential conductance and the current noise measurements agrees well with the theoretical values predicted for SWNTs.; Quantum point contacts (QPCs) in a high-mobility two-dimensional electron gas (2DEG) system have been a prototypical device used to investigate low-dimensional mesoscopic physics as well as a basic ingredient to explore quantum statistics of particles. The quantized conductance manifests ballistic transport through QPCs and it is well understood by the wave nature of quantum particles in terms of transmission probability. An additional remarkable feature has been identified as the 0.7 structure, reflecting many-body effects. An attempt to explore unresolved features in a QPC is made with a control of the electron density in a 2DEG. Non-equilibrium transport properties of differential conductance and current fluctuations in a backgated QPC is characterized.