Carbon nanotubes are attractive materials as the building block of quantum-dot based nanodevices. In particular, single-wall carbon nanotubes (SWCNTs) are interesting because they become metallic and semiconducting, depending on how they are rolled up from the graphene sheet, and they could be applied to various devices such as ultrasmall field-effect transistors, single-electron devices, quantum computing devices, and light-emitting devices. A research group at the Japanese Institute of Physical and Chemical Research (RIKEN) has made extensive experimental efforts to apply SWCNTs to single-electron devices and quantum computing devices (spin qubit) with a single quantum dot as a basic structure.
Researchers in Germany managed to integrate quantum dots (QD) into the walls of nano- and microtubes. This novel structure serves as a quantum light emitter as well as optical waveguide. This represents a major step toward the realization of flexible high quality factor optical resonators based on tubes.