Triplet exciton states in carbon nanotubes: a possible candidate for telecomm compatible qubits

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Triplet exciton states in carbon nanotubes
2021. 02. 12. 10:15
online (Teams)
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 [1] 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 [2], 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.
[1] J. Palotás et al. ACS Nano 14, 11254 (2020). (
[2] M. Negyedi et al. Rev. Sci. Instrum. 88, 013902 (2017). (