This manuscript reports the impact
of fullerene structure on the
morphology and miscibility of small molecules via a fullerene bulk
heterojunction solar cell. The small angle neutron scattering and
neutron reflectometry measurements were analyzed to provide quantifiable
measures of the morphology of the resultant mixtures, offering miscibility,
domain sizes, interfacial area between the small molecule and fullerene,
and depth profiles in the mixtures. These results indicate that the
bis-adduct fullerenes exhibit lower miscibility in small molecules.
Correlation of miscibility and morphology to photovoltaic properties
indicates that small molecule/fullerene miscibility is crucial to
rationally optimize the design of fullerenes for use in small molecule
organic photovoltaics. A higher open circuit voltage was obtained
for bis-adduct fullerene devices which, however, does not translate
to an increased power conversion efficiency. This decrease in performance
is associated with the lower miscibility of bis-fullerene, which decreases
the probability of the dissociation of excitons and enhances charge
recombination rate in the miscible region. A quantitative analysis
shows that an increase in the average separation of fullerenes in
the miscible region is detrimental to electron transport in the miscible
region, especially for a distance greater than ∼11 Å.
No-cloning theorem forbids perfect cloning of an unknown quantum state. A universal quantum cloning machine (UQCM), capable of producing two copies of any input qubit with the optimal fidelity, is of fundamental interest and has applications in quantum information processing. This is enabled by delicately tailored nonclassical correlations between the input qubit and the copying qubits, which distinguish the UQCM from a classical counterpart, but whose experimental demonstrations are still lacking. We here implement the UQCM in a superconducting circuit and investigate these correlations. The measured entanglements well agree with our theoretical prediction that they are independent of the input state and thus constitute a universal quantum behavior of the UQCM that was not previously revealed. Another feature of our experiment is the realization of deterministic and individual cloning, in contrast to previously demonstrated UQCMs, which either were probabilistic or did not constitute true cloning of individual qubits.
Holonomies, arising from non-Abelian geometric transformations of quantum states in Hilbert space, offer a promising way for quantum computation. These holonomies are not commutable and thus can be used for the realization of a universal set of quantum logic gates, where the global geometric feature may result in some noise-resilient advantages. Here we report, to our knowledge, the first on-chip realization of a non-Abelian geometric controlled-NOT gate in a superconducting circuit, which is a building block for constructing a holonomic quantum computer. The conditional dynamics is achieved in an all-to-all connected architecture involving multiple frequency-tunable superconducting qubits controllably coupled to a resonator; a holonomic gate between any two qubits can be implemented by tuning their frequencies on-resonance with the resonator and applying a two-tone drive to one of them. This gate represents an important step towards the all-geometric realization of scalable quantum computation on a superconducting platform.
We propose a method for the dynamical control in three-level open systems and realize it in the experiment with a superconducting qutrit. Our work demonstrates that in the Markovian environment for a relatively long time (3 $\mu$s), the systemic populations or coherence can still strictly follow the preset evolution paths. This is the first experiment for precisely controlling the Markovian dynamics of three-level open systems, providing a solid foundation for the future realization of dynamical control in multiple open systems. An instant application of the technique demonstrated in this experiment is to stabilize the energy of quantum batteries.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.