Formation of InAs Self-Assembled Quantum Rings on InP

Shape transformations of partially capped self-assembled InAs quantum dots grown on InP are studied. Atomic force microscopy images show large anisotropic redistribution of the island material after coverage by a 1 nm thick InP layer. The anisotropic material redistribution occurs within a few minutes and leads to a change from lens-like to elongated ring-like islands. The shape transformation is not accompanied by dot material compositional change. The formation of InAs/InP quantum rings disagrees with a previous model of InAs/GaAs ring formation that assumes that the driving force for the dot to ring transformation is the difference in surface diffusion velocity of indium and gallium atoms.Comment: 13 pages, including 2 figures and 1 table. Submitted to Appl. Phys. Let

Management and Service-aware Networking Architectures (MANA) for Future Internet Position Paper: System Functions, Capabilities and Requirements

Future Internet (FI) research and development threads have recently been gaining momentum all over the world and as such the international race to create a new generation Internet is in full swing: GENI, Asia Future Internet, Future Internet Forum Korea, European Union Future Internet Assembly (FIA). This is a position paper identifying the research orientation with a time horizon of 10 years, together with the key challenges for the capabilities in the Management and Service-aware Networking Architectures (MANA) part of the Future Internet (FI) allowing for parallel and federated Internet(s)

Near-threshold high-order harmonic spectroscopy with aligned molecules

We study high-order harmonic generation in aligned molecules close to the ionization threshold. Two distinct contributions to the harmonic signal are observed, which show very different responses to molecular alignment and ellipticity of the driving field. We perform a classical electron trajectory analysis, taking into account the significant influence of the Coulomb potential on the strong-field-driven electron dynamics. The two contributions are related to primary ionization and excitation processes, offering a deeper understanding of the origin of high harmonics near the ionization threshold. This work shows that high harmonic spectroscopy can be extended to the near-threshold spectral range, which is in general spectroscopically rich.Comment: 4 pages, 4 figure

Long-range entanglement generation via frequent measurements

A method is introduced whereby two non-interacting quantum subsystems, that each interact with a third subsystem, are entangled via repeated projective measurements of the state of the third subsystem. A variety of physical examples are presented. The method can be used to establish long range entanglement between distant parties in one parallel measurement step, thus obviating the need for entanglement swapping.Comment: 7 pages, incl. 2 figures. v2: added a few small clarifications and a referenc

Proposed experiment for the quantum "Guess my number" protocol

An experimental realization of the entanglement-assisted "Guess my number" protocol for the reduction of communication complexity, introduced by Steane and van Dam, would require producing and detecting three-qubit GHZ states with an efficiency eta > 0.70, which would require single photon detectors of efficiency sigma > 0.89. We propose a modification of the protocol which can be translated into a real experiment using present-day technology. In the proposed experiment, the quantum reduction of the multi-party communication complexity would require an efficiency eta > 0.05, achievable with detectors of sigma > 0.47, for four parties, and eta > 0.17 (sigma > 0.55) for three parties.Comment: REVTeX4, 4 pages, 1 figur