372 research outputs found
Time-Delay Polaritonics
Non-linearity and finite signal propagation speeds are omnipresent in nature,
technologies, and real-world problems, where efficient ways of describing and
predicting the effects of these elements are in high demand. Advances in
engineering condensed matter systems, such as lattices of trapped condensates,
have enabled studies on non-linear effects in many-body systems where exchange
of particles between lattice nodes is effectively instantaneous. Here, we
demonstrate a regime of macroscopic matter-wave systems, in which ballistically
expanding condensates of microcavity exciton-polaritons act as picosecond,
microscale non-linear oscillators subject to time-delayed interaction. The ease
of optical control and readout of polariton condensates enables us to explore
the phase space of two interacting condensates up to macroscopic distances
highlighting its potential in extended configurations. We demonstrate
deterministic tuning of the coupled-condensate system between fixed point and
limit cycle regimes, which is fully reproduced by time-delayed coupled
equations of motion similar to the Lang-Kobayashi equation
Grapevine DNA polymorphisms revealed by microsatellite-derived markers from soybean and rice
We report detection of DNA polymorphisms in grapevine by the use of microsatellite-flanking primer pairs from soybean and rice. These “cross species” microsatellite-derived markers were checked for their inheritance patterns in controlled grapevine crosses. They produced multiple bands that segregated and can be scored as individual genetic markers of dominant type. Employed in genetic mapping studies they offer advantages such as improved reproducibility in comparison to commonly used multi-locus marker systems like RAPDs and AFLPs.
Molecular-Level Understanding of the Ro-vibrational Spectra of NO in Gaseous, Supercritical and Liquid SF and Xe
The transition between the gas-, supercritical-, and liquid-phase behaviour
is a fascinating topic which still lacks molecular-level understanding. Recent
ultrafast two-dimensional infrared spectroscopy experiments suggested that the
vibrational spectroscopy of NO embedded in xenon and SF as solvents
provides an avenue to characterize the transitions between different phases as
the concentration (or density) of the solvent increases. The present work
demonstrates that classical molecular dynamics simulations together with
accurate interaction potentials allows to (semi-)quantitatively describe the
transition in rotational vibrational infrared spectra from the P-/R-branch
lineshape for the stretch vibrations of NO at low solvent densities to the
Q-branch-like lineshapes at high densities. The results are interpreted within
the classical theory of rigid-body rotation in more/less constraining
environments at high/low solvent densities or based on phenomenological models
for the orientational relaxation of rotational motion. It is concluded that
classical MD simulations provide a powerful approach to characterize and
interpret the ultrafast motion of solutes in low to high density solvents at a
molecular level
Directional planar antennae in polariton condensates
We report on the realization of all-optical planar microlensing for
exciton-polariton condensates in semiconductor microcavities. We utilize
spatial light modulators to structure a nonresonant pumping beam into a
planoconcave lens-shape focused onto the microcavity plane. When pumped above
condensation threshold, the system effectively becomes a directional polariton
antenna, generating an intense focused beam of coherent polaritons away from
the pump region. The effects of pump intensity, which regulates the interplay
between gain and blueshift of polaritons, as well as the geometry of
lens-shaped pump are studied and a strategy to optimize the focusing of the
condensate is proposed. Our work underpins the feasibility to guide nonlinear
light in microcavities using nonresonant excitation schemes, offering
perspectives on optically reprogrammable on-chip polariton circuitry
A 'Regent' pedigree update: ancestors, offspring and their confirmed resistance loci
'Regent' is the fungal resistant grapevine cultivar with the highest acreage in Germany and an important resistance donor in international breeding programs. It carries the resistance loci Rpv3.1 as well as Ren3 and Ren9 against downy and powdery mildew, respectively. As the parents of 'Chambourcin', the resistant paternal ancestor of 'Regent', did not coincide with the breeder's information, the germplasm repository of JKI Geilweilerhof was screened to find the missing ancestors. SSR marker analysis revealed that 'Joannes Seyve 11369' and 'Plantet' are the true parents of 'Chambourcin' and not 'Seyve Villard 12-417' and 'Chancellor'. Furthermore, the origin of the resistance loci Ren3 and Ren9 could be traced back to the genotypes 'Seibel 4614' and 'Munson'. Since the breeder Hermann Jaeger mentioned 'Munson' as a direct descendant of Vitis aestivalis Michx. var. linsecomii (Buckley) L. H. Bailey and Vitis rupestris Scheele, one of these wild species might have been the donor of the loci
Zero Order Estimates for Analytic Functions
The primary goal of this paper is to provide a general multiplicity estimate.
Our main theorem allows to reduce a proof of multiplicity lemma to the study of
ideals stable under some appropriate transformation of a polynomial ring. In
particular, this result leads to a new link between the theory of polarized
algebraic dynamical systems and transcendental number theory. On the other
hand, it allows to establish an improvement of Nesterenko's conditional result
on solutions of systems of differential equations. We also deduce, under some
condition on stable varieties, the optimal multiplicity estimate in the case of
generalized Mahler's functional equations, previously studied by Mahler,
Nishioka, Topfer and others. Further, analyzing stable ideals we prove the
unconditional optimal result in the case of linear functional systems of
generalized Mahler's type. The latter result generalizes a famous theorem of
Nishioka (1986) previously conjectured by Mahler (1969), and simultaneously it
gives a counterpart in the case of functional systems for an important
unconditional result of Nesterenko (1977) concerning linear differential
systems. In summary, we provide a new universal tool for transcendental number
theory, applicable with fields of any characteristic. It opens the way to new
results on algebraic independence, as shown in Zorin (2010).Comment: 42 page
Inferring the Scale of OpenStreetMap Features
International audienceTraditionally, national mapping agencies produced datasets and map products for a low number of specified and internally consistent scales, i.e. at a common level of detail (LoD). With the advent of projects like OpenStreetMap, data users are increasingly confronted with the task of dealing with heterogeneously detailed and scaled geodata. Knowing the scale of geodata is very important for mapping processes such as for generalization of label placement or land-cover studies for instance. In the following chapter, we review and compare two concurrent approaches at automatically assigning scale to OSM objects. The first approach is based on a multi-criteria decision making model, with a rationalist approach for defining and parameterizing the respective criteria, yielding five broad LoD classes. The second approach attempts to identify a single metric from an analysis process, which is then used to interpolate a scale equivalence. Both approaches are combined and tested against well-known Corine data, resulting in an improvement of the scale inference process. The chapter closes with a presentation of the most pressing open problem
Realizing the classical XY Hamiltonian in polariton simulators.
The vast majority of real-life optimization problems with a large number of degrees of freedom are intractable by classical computers, since their complexity grows exponentially fast with the number of variables. Many of these problems can be mapped into classical spin models, such as the Ising, the XY or the Heisenberg models, so that optimization problems are reduced to finding the global minimum of spin models. Here, we propose and investigate the potential of polariton graphs as an efficient analogue simulator for finding the global minimum of the XY model. By imprinting polariton condensate lattices of bespoke geometries we show that we can engineer various coupling strengths between the lattice sites and read out the result of the global minimization through the relative phases. Besides solving optimization problems, polariton graphs can simulate a large variety of systems undergoing the U(1) symmetry-breaking transition. We realize various magnetic phases, such as ferromagnetic, anti-ferromagnetic, and frustrated spin configurations on a linear chain, the unit cells of square and triangular lattices, a disordered graph, and demonstrate the potential for size scalability on an extended square lattice of 45 coherently coupled polariton condensates. Our results provide a route to study unconventional superfluids, spin liquids, Berezinskii-Kosterlitz-Thouless phase transition, and classical magnetism, among the many systems that are described by the XY Hamiltonian
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