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nanotimes News in Brief

– the cultivation of artificial tissue – thanks to their high porosity.

Contact: Annika Thormann, Fraunhofer Institute for Mechanics of Materials, Halle facilities, Phone +49 345 5589-281: http://www.iwm.fraunhofer.de/profil/iwm-standorte/ institutsteil-halle/

Researchers at the Pohang University of Science and Technology, Korea, have synthesized a new type of composite made from reduced graphene oxide and magnetite that could effectively remove arsenic from drinking water.

Vimlesh Chandra, Jaesung Park, Young Chun, Jung Woo Lee, In-Chul Hwang and Kwang S. Kim: Water-Dispersi- ble Magnetite-Reduced Graphene Oxide Composites for Arsenic Removal, In: ACS Nano, Vol. 4(2010), Issue 7, Pages 3979-3986, DOI:10.1021/nn1008897: http://dx.doi.org/10.1021/nn1008897

Physicists of the University of Innsbruck, Austria have experimentally observed a quantum phe- nomenon, where an arbitrarily weak perturbation causes atoms to build an organized structure from an initially unorganized one.

The Innsbruck physicists have observed a “pinning transition” from a superfluid (“Luttinger liquid”) to an insulated phase (“Mott-insulator”). In their experiment they showed that for strongly interac- ting atoms an additional weak lattice potential was sufficient to pin the atoms to fixed positions along the wire (“pinning”). The atoms were cooled down

10-07/08 :: July/August 2010

to nearly absolute zero and were in their quantum mechanical ground state. “It is not thermal fluctua- tions that induce the phase transition,” stresses PhD student Elmar Haller, who is also first author of the study. “In fact, the atoms are already correlated due to strong repulsive interaction and only need a small push to align regularly along the optical lattice,” explains Haller. When the lattice is removed, the atoms return to a superfluid state.

Elmar Haller, Russell Hart, Manfred J. Mark, Johann G. Danzl, Lukas Reichsöllner, Mattias Gustavsson, Marcel- lo Dalmonte, Guido Pupillo, Hanns-Christoph Nägerl: Pinning quantum phase transition for a Luttinger li- quid of strongly interacting bosons, In: Nature, Volume 466(2010), Number 7306, July 29, 2010, Pages 597-600, DOI:10.1038/nature09259: http://dx.doi.org/10.1038/nature09259

Researchers at the University of California-Los Angeles synthesized crystalline solids with exten- ded non-interpenetrating three-dimensional crystal structures that support well-defined pores with internal diameters of up to 48 Angströms.

Hiroyasu Furukawa, Nakeun Ko, Yong Bok Go, Naoki Ara- tani, Sang Beom Choi, Eunwoo Choi, A. Özgür Yazaydin, Randall Q. Snurr, Michael O’Keeffe, Jaheon Kim, Omar M. Yaghi: Ultra-High Porosity in Metal-Organic Frame- works, In: Science Express, July 01, 2010, DOI:10.1126/ science.1192160:

http://dx.doi.org/10.1126/science.1192160