The scattering cross sections of charm mesons with hadrons such as the pion, rho meson, and nucleon are studied in an effective Lagrangian. In heavy ion collisions, rescattering of produced charm mesons by hadrons affects the invariant mass spectra of both charm meson pairs and dileptons resulting from their decays. These effects are estimated for heavy ion collisions at Super Proton Synchrotron energies and are found to be significant.

Charmonium production from the hadron gas formed in ultra-relativistic heavy-ion collisions is studied. Using the J/ψ-hadron absorption cross section determined from the nonperturbative quark-exchange model, which has a peak value similar to that used in the comover model for J/ψ suppression and a thermally averaged value consistent from that extracted from J/ψ data in heavy-ion collisions, we find that J/ψ production from the hadron gas is negligible in heavy-ion collisions at RHIC energies but is important at LHC energies as a result of the large number of charm mesons produced at higher energy collisions. The number of J/ψ produced from these secondary collisions at LHC may be comparable to that of primary J/ψ's, which are expected to be dissociated in the quark-gluon plasma created in the collisions, leading thus to a possible absence of J/ψ suppression. Similar results are obtained for ψ ′ production in ultra-relativistic heavy-ion collisions.

We utilize the asymmetric random telegraph wave-based instantaneous noisebase logic scheme to represent the problem of drawing numbers from a hat, and we consider two identical hats with the first 2 N integer numbers. In the first problem, Alice secretly draws an arbitrary number from one of the hats, and Bob must find out which hat is missing a number. In the second problem, Alice removes a known number from one of the hats and another known number from the other hat, and Bob must identify these hats. We show that, when the preparation of the hats with the numbers is accounted for, the noise-based logic scheme always provides an exponential speed-up and/or it requires exponentially smaller computational complexity than deterministic alternatives. Both the stochasticity and the ability to superpose numbers are essential components of the exponential improvement.

Searching for multifunctional materials with tunable magnetic and optical properties has been a critical task toward the implementation of future integrated optical devices. Vertically aligned nanocomposite (VAN) thin films provide a unique platform for multifunctional material designs. Here, a new metal–oxide VAN has been designed with plasmonic Au nanopillars embedded in a ferromagnetic La0.67Sr0.33MnO3 (LSMO) matrix. Such Au–LSMO nanocomposite presents intriguing plasmon resonance in the visible range and magnetic anisotropy property, which are functionalized by the Au and LSMO phase, respectively. Furthermore, the vertically aligned nanostructure of metal and dielectric oxide results in the hyperbolic property for near-field electromagnetic wave manipulation. Such optical and magnetic response could be further tailored by tuning the composition of Au and LSMO phases.

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Vertically aligned nanocomposites (VAN) thin films present as an intriguing material family for achieving novel functionalities. However, most of the VAN structures tend to grow in a random fashion, hindering the future integration in nanoscale devices. Previous efforts for achieving ordered nanopillar structures have been focused on specific systems, and rely on sophisticated lithography and seeding techniques, making large area ordering quite difficult. In this work, a new technique is presented to produce self-assembled nanocomposites with long-range ordering through selective nucleation of nanocomposites on termination patterned substrates. Specifically, SrTiO (001) substrates have been annealed to achieve alternating chemical terminations and thus enable selective epitaxy during the VAN growth. La Sr MnO :CeO (LSMO):CeO nanocomposites, as a prototype, are demonstrated to form well-ordered rows in matrix structure, with CeO (011) domains selectively grown on SrO terminated area, showing enhanced functionality. This approach provides a large degree of long-range ordering for nanocomposite growth that could lead to unique functionalities and takes the nanocomposites one step closer toward future nanoscale device integration.

Self-assembled vertically aligned metal-oxide (Ni-CeO2) nanocomposite thin films with novel multifunctionalities have been successfully deposited by a one-step growth method. The novel nanocomposite structures presents high-density Ni-nanopillars vertically aligned in a CeO2 matrix. Strong and anisotropic magnetic properties have been demonstrated, with a saturation magnetization (Ms) of ∼175 emu cm-3 and ∼135 emu cm-3 for out-of-plane and in-plane directions, respectively. Such unique vertically aligned ferromagnetic Ni nanopillars in the CeO2 matrix have been successfully incorporated in high temperature superconductor YBa2Cu3O7 (YBCO) coated conductors as effective magnetic flux pinning centers. The highly anisotropic nanostructures with high density vertical interfaces between the Ni nanopillars and CeO2 matrix also promote the mixed electrical and ionic conductivities out-of-plane and thus demonstrate great potential as nanocomposite anode materials for solid oxide fuel cells and other potential applications requiring anisotropic ionic transport properties.

Materials with magneto-optic coupling properties are highly coveted for their potential applications ranging from spintronics and optical switches to sensors. In this work, a new, three-phase Au–Fe–La0.5Sr0.5FeO3 (LSFO) hybrid material grown in a vertically aligned nanocomposite (VAN) form has been demonstrated. This three-phase hybrid material combines the strong ferromagnetic properties of Fe and the strong plasmonic properties of Au and the dielectric nature of the LSFO matrix. More interestingly, the immiscible Au and Fe phases form Au-encapsulated Fe nanopillars, embedded in the LSFO matrix. Multifunctionalities including anisotropic optical dielectric properties, plasmonic properties, magnetic anisotropy, and room-temperature magneto-optic Kerr effect coupling are demonstrated. The single-step growth method to grow the immiscible two-metal nanostructures (i.e., Au and Fe) in the complex hybrid material form opens exciting new potential opportunities for future three-phase VAN systems with more versatile metal selections.