Credit: Alan Stonebraker

Figure 1: Trions in carbon nanotubes—Coulomb-bound carrier complexes consisting of one electron and two holes with opposite spin orientations—would be highly beneficial for optical spin manipulation and for the investigation of correlated carrier dynamics in one-dimensional systems, thanks to their unpaired spins. In this work the authors report evidence that trions can be optically excited in carefully prepared $p$-doped nanotubes and they are more stable than expected earlier.