58,905 research outputs found
Vortices, zero modes and fractionalization in bilayer-graphene exciton condensate
A real-space formulation is given for the recently discussed exciton
condensate in a symmetrically biased graphene bilayer. We show that in the
continuum limit an oddly-quantized vortex in this condensate binds exactly one
zero mode per valley index of the bilayer. In the full lattice model the zero
modes are split slightly due to intervalley mixing. We support these results by
an exact numerical diagonalization of the lattice Hamiltonian. We also discuss
the effect of the zero modes on the charge content of these vortices and deduce
some of their interesting properties.Comment: (v2) A typo in Fig. 1 and a slight error in Eq. (4) corrected; all
the main results and conclusions remain unchange
Enabling Flexible and Robust Business Process Automation for the Agile Enterprise
During the last decade process-aware information systems (PAISs) have become increasingly popular to digitize business processes and to effectively support them at the operational level. In many application domains, however, PAISs will not be accepted by users if rigidity comes with them. Ensuring PAIS robustness, in turn, becomes extremely complicated if high flexibility demands need to be fulfilled. To cope with the dynamic nature of business processes, we developed AristaFlow, a next generation process management technology that enables comprehensive process lifecycle support. In addition to standard process management services, AristaFlow can handle exceptions, change the execution of running business cases on the fly, efficiently deal with uncertainty, and support the evolution of business processes over time. This paper discusses how AristaFlow assists the various stakeholders of a PAIS to cope with errors and exceptional situations, while still meeting robustness needs. In particular, we focus on new error handling procedures and capabilities utilizing the flexibility provided by ad-hoc changes
Growth and survival of nearshore fishes in Lake Michigan
Illinois Department of Natural resources Grant/Contract No: F-138INHS Technical Report Prepared for Illinois Department of Natural resource
Shape-induced phenomena in the finite size antiferromagnets
It is of common knowledge that the direction of easy axis in the finite-size
ferromagnetic sample is controlled by its shape. In the present paper we show
that a similar phenomenon should be observed in the compensated
antiferromagnets with strong magnetoelastic coupling. Destressing energy which
originates from the long-range magnetoelastic forces is analogous to
demagnetization energy in ferromagnetic materials and is responsible for the
formation of equilibrium domain structure and anisotropy of macroscopic
magnetic properties. In particular, crystal shape may be a source of additional
uniaxial magnetic anisotropy which removes degeneracy of antiferromagnetic
vector or artificial 4th order anisotropy in the case of a square cross-section
sample. In a special case of antiferromagnetic nanopillars shape-induced
anisotropy can be substantially enhanced due to lattice mismatch with the
substrate. These effects can be detected by the magnetic rotational torque and
antiferromagnetic resonance measurements.Comment: 7 pages, 5 figures, to appear in Phys. Rev. B, v.75, N17, 200
First record of an Odontaspidid shark in Ascension Island waters
The occurrence of the poorly understood shark species Odontapsis ferox is reported at an oceanic seamount in the central south Atlantic, within the Exclusive Economic Zone of Ascension Island. The presence of the species at this location is confirmed by the discovery of a tooth embedded in scientific equipment, and footage of at least one animal on autonomous underwater video. The new record of this shark species at this location demonstrates the knowledge gaps which still exist at many remote, oceanic structures and their candidacy for status as important conservation areas.info:eu-repo/semantics/publishedVersio
A tunable, dual mode field-effect or single electron transistor
A dual mode device behaving either as a field-effect transistor or a single
electron transistor (SET) has been fabricated using silicon-on-insulator metal
oxide semiconductor technology. Depending on the back gate polarisation, an
electron island is accumulated under the front gate of the device (SET regime),
or a field-effect transistor is obtained by pinching off a bottom channel with
a negative front gate voltage. The gradual transition between these two cases
is observed. This dual function uses both vertical and horizontal tunable
potential gradients in non-overlapped silicon-on-insulator channel
Feynman versus Bakamjian-Thomas in Light Front Dynamics
We compare the Bakamjian-Thomas (BT) formulation of relativistic few-body
systems with light front field theories that maintain closer contact with
Feynman diagrams. We find that Feynman diagrams distinguish Melosh rotations
and other kinematical quantities belonging to various composite subsystem
frames that correspond to different loop integrals. The BT formalism knows only
the rest frame of the whole composite system, where everything is evaluated.Comment: 5 page
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