Novel Nanotube Multiquantum Dot Devices

Abstract

Addressable quantum states well isolated from the environment are of considerable interest for quantum information science and technology. Carbon nanotubes are an appealing system, since a perfect crystal can be grown without any missing atoms and its cylindrical structure prevents ill-defined atomic arrangement at the surface. Here, we develop a reliable process to fabricate compact multielectrode circuits that can sustain the harsh conditions of the nanotube growth. Nanotubes are suspended over multiple gate electrodes, which are themselves structured over narrow dielectric ridges to reduce the effect of the charge fluctuators of the substrate. We measure high-quality double- and triple-quantum dot charge stability diagrams. Transport measurements through the triple-quantum dot indicate long-range tunneling of single electrons between the left and right quantum dots. This work paves the way to the realization of a new generation of condensed-matter devices in an ultraclean environment, including spin qubits, mechanical qubits, and quantum simulators.

Spintronic interactions between topological edge states in chiral carbon nanotubes: a natural helical symmetry approach

“…CNTs have shown advantages in field effect transistors (FETs) 26,27 and are expected to have potential in single electron transistors (SETs), multi quantum dot applications, etc. 15,16,28,29 In this work, we investigate the topological properties of chiral CNTs with four representative edge terminations in the scheme of the natural helical crystal lattice (NHCL) method. [30][31][32] The NHCL method applies the skew symmetry of the chiral CNTs and uses the helical periodic unit cells, which greatly lowers the computational cost compared to the conventional translational crystal lattice (TCL) scheme.…”