Triplet exciton states in carbon nanotubes
2021. 02. 12. 10:15
Ferenc Simon (BME)
Finding a suitable qubit which emits in the near infrared range is the holy grail of ongoing quantum telecommunication research. We propose the recently discovered  triplet exciton states in carbon nanotubes for this purpose, whose fundamental properties (energy structure, relaxation time) are now established. I first review the photophysics of best known solid state qubit, the nitrogen-vacancy (NV) center in diamond, which nominally emits in the visible range, far from the so-called telecom frequency windows. I then describe our experimental efforts in developing a specialized optically detected magnetic resonance spectrometer , which allowed detection of the otherwise dark triplet excitons in single-walled carbon nanotubes. I show that the nanotube geometry allows for a fine tuning of the emission energies. I present evidence for a singlet-triplet splitting due to quantum confinement and the observation of an exciton energy transfer between nanotubes, which may allow for quantum information transcription.
 J. Palotás et al. ACS Nano 14, 11254 (2020). (https://arxiv.org/pdf/2009.06314.pdf)
 M. Negyedi et al. Rev. Sci. Instrum. 88, 013902 (2017). (https://arxiv.org/pdf/1610.01177.pdf)