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yexuqing

木虫之王 (文学泰斗)

太阳系系主任

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专业: 数论

[交流] 关于玻色玻璃相的思考已有3人参与

关于玻色玻璃相的思考

发表日期：2012年9月20日

玻色-爱因斯坦凝聚(BEC)和超流动性是已经被研究很多的“玻色子系综”在低温下可以表现出来的异常宏观量子力学状态的例子。我们所不太熟悉的是“玻璃”态，这种状态据预测在无序存在时会对相互作用的玻色子出现，但迄今为止在实验中却没有观测到。现在，Rong Yu等人发现，一种掺杂的量子磁体中的磁激发非常适合实现和研究这种行为。（Link to Article p. 379）

doi: 10.1038/nature11406
Bose glass and Mott glass of quasiparticles in a doped quantum magnet
Rong Yu1 Liang Yin2 Neil S. Sullivan2 J. S. Xia2 Chao Huan2 Armando Paduan-Filho3 Nei F. Oliveira Jr3 Stephan Haas4 Alexander Steppke5 Corneliu F. Miclea6, 7 Franziska Weickert6 Roman Movshovich6 Eun-Deok Mun6 Brian L. Scott6 Vivien S. Zapf6 Tommaso Roscilde8
Affiliations Contributions Corresponding author Journal name:
Nature
Volume:
489,
Pages:
379–384
Date published:
(20 September 2012)
DOI:
doi:10.1038/nature11406
Received 14 May 2012 Accepted 11 July 2012 Published online 19 September 2012
The low-temperature states of bosonic fluids exhibit fundamental quantum effects at the macroscopic scale: the best-known examples are Bose–Einstein condensation and superfluidity, which have been tested experimentally in a variety of different systems. When bosons interact, disorder can destroy condensation, leading to a ‘Bose glass’. This phase has been very elusive in experiments owing to the absence of any broken symmetry and to the simultaneous absence of a finite energy gap in the spectrum. Here we report the observation of a Bose glass of field-induced magnetic quasiparticles in a doped quantum magnet (bromine-doped dichloro-tetrakis-thiourea-nickel, DTN). The physics of DTN in a magnetic field is equivalent to that of a lattice gas of bosons in the grand canonical ensemble; bromine doping introduces disorder into the hopping and interaction strength of the bosons, leading to their localization into a Bose glass down to zero field, where it becomes an incompressible Mott glass. The transition from the Bose glass (corresponding to a gapless spin liquid) to the Bose–Einstein condensate (corresponding to a magnetically ordered phase) is marked by a universal exponent that governs the scaling of the critical temperature with the applied field, in excellent agreement with theoretical predictions. Our study represents a quantitative experimental account of the universal features of disordered bosons in the grand canonical ensemble.

http://www.nature.com/nature/jou ... pdf/nature11406.pdf

[ Last edited by yexuqing on 2012-9-21 at 13:06 ]

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