Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Conventional surface plasmons have a wave vector exceeding that of light in vacuum, and therefore cannot be directly excited by light that is simply incident on the surface. However, we propose that a plasmonpolariton state can be formed at the boundary between a metal and a dielectric Bragg mirror that can have a zero in-plane wave vector and therefore can be produced by direct optical excitation. In analogy with the electronic states at a crystal surface proposed by Tamm, we call these excitations Tamm plasmons, and predict that they may exist in both the TE and TM polarizations and are characterized by parabolic dispersion relations.

(2010) 'Self-catalyzed, pure zincblende GaAs nanowires grown on Si (111) Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. We report on the Au-free molecular beam epitaxy growth of coherent GaAs nanowires directly on Si͑111͒ substrates. The growth is catalyzed by liquid Ga droplets formed in the openings of a native oxide layer at the initial growth stage. Transmission electron microscopy studies demonstrate that the nanowires are single crystals having the zincblende structure along their length ͑apart from a thin wurtzite region directly below the Ga droplet͒, regardless of their diameter ͑70-80 nm͒ and the growth temperature range ͑560-630°C͒. We attribute the observed phase purity to a much lower surface energy of liquid Ga than that of Au-Ga alloys, which makes triple line nucleation energetically unfavorable. The change in growth catalyst to a liquid metal with a lower energy suppresses the ͑more usual͒ formation of wurtzite nuclei on surface energetic grounds. These results can provide a distinct method for the fabrication of chemically pure and stacking-fault-free zincblende nanowires of III-V compounds on silicon.

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