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发表于 2009-9-10 11:19
来自： 浙江省宁波市 电信
本帖最后由 gohomeman1 于 2009-9-10 11:22 编辑
http://www.sciencemag.org/cgi/content/abstract/sci;1178868v1?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=monopole&searchid=1&FIRSTINDEX=0&sortspec=date&resourcetype=HWCIT
Reports Submitted on July 9, 2009
Accepted on August 26, 2009
Dirac Strings and Magnetic Monopoles in Spin Ice Dy2Ti2O7D. J. P. Morris 1*, D. A. Tennant 2*, S. A. Grigera 3*, B. Klemke 2, C. Castelnovo 4, R. Moessner 5, C. Czternasty 1, M. Meissner 1, K. C. Rule 1, J.-U. Hoffmann 1, K. Kiefer 1, S. Gerischer 1, D. Slobinsky 6, R. S. Perry 7
1 Helmholtz-Zentrum Berlin für Materialien und Energie, Glienicker Str. 100, Berlin D-14109, Germany.
2Helmholtz-Zentrum Berlin für Materialien und Energie, Glienicker Str.100, Berlin D-14109, Germany.; Institut für Festkörperphysik,Technische Universität Berlin, Hardenbergstr. 36, Berlin D-10623,Germany.
3 School of Physics and Astronomy,North Haugh, St Andrews, Fife KY15 9SS, UK.; Instituto de Física deLíquidos y Sistemas Biológicos, CONICET, UNLP, La Plata, Argentina.
4 Rudolf Peierls Centre for Theoretical Physics, 1 Keble Road, Oxford OX1 3NP, UK.
5 Max Planck Institut für Physik Komplexer Systeme, Nöthnitzer Str. 38, D-01187 Dresden, Germany.
6 School of Physics and Astronomy, North Haugh, St Andrews, Fife KY15 9SS, UK.
7 School of Physics, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, UK.
* To whom correspondence should be addressed.
D. J. P. Morris , E-mail: jonathan.morris@helmholtz-berlin.de
D. A. Tennant , E-mail: tennant@helmholtz-berlin.de
S. A. Grigera , E-mail: sag2@st-and.ac.uk
While sources of magnetic fields—magnetic monopoles—have so far proven elusive as elementary particles, several scenarios have been proposed recently in condensed matter physics of emergent quasiparticles resembling monopoles. A particularly simple proposition pertains to spin ice on the highly frustrated pyrochlore lattice. The spin ice state is argued to be well-described by networks of aligned dipoles resembling solenoidal tubes—classical, and observable, versions of a Dirac string. Where these tubes end, the resulting defect looks like a magnetic monopole. We demonstrate, by diffuse neutron scattering, the presence of such strings in the spin ice Dy2Ti2O7. This is achieved by applying a symmetry-breaking magnetic field with which we can manipulate density and orientation of the strings. In turn, heat capacity is described by a gas of magnetic monopoles interacting via a magnetic Coulomb interaction. |
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IP卡
狗仔卡
置顶卡
变色卡
千斤顶
显身卡
真奇妙
只在n年前听说过“磁单极子”这个名词。