  Quantum computation and quantum information processing are emerging
technologies that have potential to overcome the physical limitation of
traditional computation systems. Present quantum systems based on photons,
atoms and molecules, however, all face challenges such as short coherence time,
requirement of ultralow temperature and/or high vacuum, and lack of
scalability. We report a new type of molecular qubits and nanoparticle
ensembles based on thermally controllable transformation between J-aggregation
and monomeric states of molecular chromophores, using pyrrolopyrrole cyanine
tethered with polymeric chains such as polycaprolactones as an example. Such
supramolecular quantum systems, resembling some feature of light harvesting
complexes in photosynthesis, provide new opportunities for manipulating quantum
in-formation under mild conditions, which do not require complicated
ultra-cooling and/or high vacuum often involved in present superconducting
qubits or Rydberg atoms for quantum computation and information processing.
