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arXiv 1003.0010hep-thcond-mat.str-el
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磁和超导体全息模型中的量子相变

Quantum phase transitions in holographic models of magnetism and superconductors

Nabil Iqbal, Hong Liu, Márk Mezei, Qimiao Si

摘要:

我们研究了一个实现“反铁磁”相的全息模型,在该模型中,代表自旋的整体SU(2)对称性由于有限电荷密度的存在而被打破为U(1)。这涉及到带电AdS黑洞中中性标量场的凝聚。我们观察到,中性和带电(如在标准全息超导体)的序参数的相变可以驱动到零温度的UV共形尺寸的序参量的调谐,导致在量子相变的Berezinskiii-Kosterlitz-无卤型。我们还描述了反铁磁相和一个外部强迫铁磁相,表明它们包含预期的自旋波与线性和二次色散分别。

英文摘要:

We study a holographic model realizing an "antiferromagnetic" phase in which a global SU(2) symmetry representing spin is broken down to a U(1) by the presence of a finite electric charge density. This involves the condensation of a neutral scalar field in a charged AdS black hole. We observe that the phase transition for both neutral and charged (as in the standard holographic superconductor) order parameters can be driven to zero temperature by a tuning of the UV conformal dimension of the order parameter, resulting in a quantum phase transition of the Berezinskii-Kosterlitz-Thouless type. We also characterize the antiferromagnetic phase and an externally forced ferromagnetic phase by showing that they contain the expected spin waves with linear and quadratic dispersions respectively.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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