Our primary interest is in the development and engineering of photonic and optoelectronic devices that would allow for manipulation of quantum states, as well as understanding the underlying physics in the operation of such devices. We exploit state-of-the-art semiconductor processing technology to fabricate nanoscale devices and perform experiments that combine microspectroscopy with electronic techniques. Our current focus is on devices that utilize individual single-walled carbon nanotubes.
Introduction to single-walled carbon nanotubes
A sheet made of carbon atoms arranged in a honeycomb lattice is called a graphene sheet. Single-walled carbon nanotubes are made by rolling up such a graphene sheet into a tube. What's really interesting about single walled carbon nanotubes is that their electronic structure can become either semiconducting or metallic depending on how it is rolled up. Single-walled carbon nanotubes have diameters of only a few nanometers, but they can grow as long as a millimeter, making it fairly easy to fabricate devices with individual nanotubes.
Optical properties of carbon nanotubesCarbon nanotubes have unique optical properties because of their one-dimensional structure.
- Exciton diffusion in carbon nanotubes
- Giant circular dichroism in individual air-suspended carbon nanotubes
- Exciton-exciton annihilation in air-suspended carbon nanotubes
- Room-temperature single photon emission from air-suspended carbon nanotubes
- Single carbon nanotubes as ultrasmall all-optical memories
Carbon nanotube optoelectronicsSemiconducting carbon nanotubes have direct bandgap, making them suitable for optoelectronic devices.
- Gate-induced blueshift and quenching of photoluminescence in carbon nanotubes
- Spontaneous exciton dissociation in carbon nanotubes
- Stark effect of excitons in individual air-suspended carbon nanotubes
- Gate-controlled generation of optical pulse trains using individual carbon nanotubes
- Gate-voltage induced trions in suspended carbon nanotubes
- Electric-field induced activation of dark excitonic states in carbon nanotubes
- Cold exciton electroluminescence from air-suspended carbon nanotube split-gate devices
Carbon nanotube photonicsIntegrating nanotube light emitters with photonic structures may open up possibilities for nanoscale optical circuits.
- Enhancement of carbon nanotube photoluminescence by photonic crystals
- Optical coupling of individual carbon nanotube emitters to silicon microdisk resonators
- High efficiency coupling of individual carbon nanotubes to photonic crystal nanobeam cavities
- Localized guided-mode and cavity-mode double resonance in photonic crystal nanocavities
- Spectral tuning of optical coupling between air-mode nanobeam cavities and individual carbon nanotubes