AbstractThe use of low-energy deep-red (DR) and near-infrared (NIR) light to excite chromophores enables catalysis to ensue across barriers such as materials and tissues. Herein, we report the detailed photophysical characterization of a library of OsII polypyridyl photosensitizers that absorb low-energy light. By tuning ligand scaffold and electron density, we access a range of synthetically useful excited state energies and redox potentials.1 Introduction1.1 Scope1.2 Measuring Ground-State Redox Potentials1.3 Measuring Photophysical Properties1.4 Synthesis of Osmium Complexes2 Properties of Osmium Complexes2.1 Redox Potentials of Os(L)2-Type Complexes2.2 Redox Potentials of Os(L)3-Type Complexes2.3 UV/Vis Absorption and Emission Spectroscopy3 Conclusions
Due to their substantial fluorescence quantum yields in the crystalline phase, propeller-shaped molecules have recently gained significant attention as potential emissive materials for optoelectronic applications. For the family of cyclopentadiene derivatives, light-emission is highly dependent on the nature of heteroatomic substitutions. In this paper, we investigate excited state relaxation pathways in the tetraphenyl-furan molecule (TPF), which in contrast with other molecules in the family, shows emission quenching in the solid-state. For the singlet manifold, our calculations show nonradiative pathways associated with C-O elongation are blocked in both vacuum and the solid state. A fraction of the population can be transferred to the triplet manifold and, subsequently, to the ground state in both phases. This process is expected to be relatively slow due to the small spin-orbit couplings between the relevant singlet-triplet states. Emission quenching in crystalline TPF seems to be in line with more efficient exciton hopping rates. Our simulations help clarify the role of conical intersections, population of the triplet states and crystalline structure in the emissive response of propeller-shaped molecules.
We analyse a method for the construction of the potential-energy function from the moments of the ground-state density. The sum rule on which some expressions are based appear to be wrong, as well as the moments and potential-energy functions derived for some illustrative examples.
Fast, large area patterning of arbitrary structures down to the nanometre scale is of great interest for a range of applications including the semiconductor industry, quantum electronics, nanophotonics and others. It was recently proposed that nanometre-resolution mask lithography can be realised by sending metastable helium atoms through a binary holography mask consisting of a pattern of holes. However, these first calculations were done using a simple scalar wave approach, which did not consider the dispersion force interaction between the atoms and the mask material. To access the true potential of the idea, it is necessary to access how this interaction affects the atoms. Here we present a theoretical study of the dispersion force interaction between an atom and a dielectric membrane with a hole. We look at metastable and ground state helium, using experimentally realistic wavelengths (0.05-1 nm) and membrane thicknesses (5-50 nm). We find that the effective hole radius is reduced by around 1-7 nm for metastable helium and 0.5-3.5 nm for ground-state helium. As expected, the reduction is largest for thick membranes and slow atoms.
We have considered and alternating spin-½/spin-1 chain with nearest-neighbor (J1), next-nearest neighbor (J2) antiferromagnetic Heisenberg interactions along with z-component of the Dzyaloshinskii-Moriya(DM) (Dz) interaction. The Hamiltonian has been studied using (a) Linear Spin-Wave Theory(LSWT) and (b) Density Matrix Renormalization Group (DMRG). The system had been reported earlier as a classical ferrimagnet only when nearest neighbor exchange interactions are present. Both the antiferromagnetic next-nearest neighbor interactions and DM interactions introduce strong quantum ﬂuctuations and due to which all the signatures of ferrimagnetism vanishes. We ﬁnd that the nonzero J2 introduces strong quantum ﬂuctuations in each of the spin sites due to which the z-components of both spin-1 and spin-1/2 sites average out to be zero. The ground state becomes a singlet. The presence of J1 along with Dzintroduces a short range order but develops long range order along the XY plane. J1 along with J2induces competing phases with structure factor showing sharp and wide peaks, at two diﬀerent angles reﬂecting the spin spiral structure locally as well as in the underlying lattice. Interestingly, we ﬁnd that the Dz term removes the local spin spiral structure in z-direction, while developing a spiral order in the XY plane.
In this paper, we give a further discussion of short-distance teleportation. We propose bidirectional, rotation and cyclic rotation teleportation schemes for short-distance participants, respectively. In our bidirectional transmission scheme, the quantum channel is still an EPR pair and an auxiliary qubit in the ground state [Formula: see text], and two participants can transmit an unknown single-qubit state to each other. In the rotation and cyclic rotation schemes, bidirectional transmission is performed between two adjacent participants in turn. The unknown state qubits of the participants collapse into the ground state after one bidirectional transmission, and can be used as auxiliary qubits in subsequent bidirectional transmission. After a complete state rotation, each participant has held the unknown state of the other participants, and the last one owned by the participant is still the original unknown state. Although the schemes we proposed are applicable to a small range of transmission, they have certain advantages in saving quantum resources.
An impact of nonperturbatively treated soft gluon modes on the value of anomalous magnetic moment of muon a_µ is studied within the mean-field approach to QCD vacuum and hadronization. It is shown that radial excitations of vector mesons strongly enhance contribution of hadronic vacuum polarization to a_µ, doubling the contribution of one-meson processes compared to the result for ground state mesons. The mean field also strongly influences the hadronic light-by-light scattering contribution due to the Wilson line in quark propagators.