First observation of room-temperature trions(electron-hole-hole complexes) in carbon nanotubes
Since the first prediction by Lampert in 1958, three-body complexes of
one electron and two holes, called “trions” or “charged excitons”,
have been extensively studied in various inorganic semiconductors.
To date, however, trions have been observed only at very low temperatures
(<50K) in the conventional semiconductor quantum wells and quantum dots,
because trions are easily broken by lattice vibrations.
In this study, we report the first observation of trions in hole-doped
carbon nanotubes.
Since the attractive Coulomb interaction is greatly enhanced in the
one-dimensional structure of 1-nm diameter, the trions in carbon nanotubes
are stable even at room temperature. In addition, carriers in carbon nanotubes
have very long spin relaxation and coherence times because of the weak
spin-orbit
coupling. Thus, the room-temperature trions in carbon nanotubes will provide a
fascinating stage both for understanding of the many-particle bound states and
for realization of quantum computing using the optical spin control in
carbon-based materials.
