Electric conductivity with the magnetic field and the chiral anomaly in a holographic QCD model
Electric conductivity with the magnetic field and the chiral anomaly in a holographic QCD model
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DOI：
10.1103/physrevd.105.054016
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发表时间：
2021-06
影响因子：
5
通讯作者：
K. Fukushima;Akitoshi Okutsu
中科院分区：
文献类型：
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作者：
K. Fukushima;Akitoshi Okutsu
我们利用具有不同磁场B和手性异常强度的全息QCD模型，即Sakai-Sugimoto模型，计算了定义QCD物质的电导率σ。在确认了B = 0时估计的σ与lattice-QCD结果一致后，我们研究了B = 0时Chern-Simons项中的α系数控制手性异常强度的情况。我们的结果表明，横向电导率σ⊥被抑制为。与温度固定为T = 0.2 GeV时B = 0的情况相比，在B ~ 1 GeV时为70%。由于Sakai-Sugimoto模型具有无质量费米子，当b6 = 0时，纵向电导率σ‖会由于物质手性的产生而发散。然而，有可能从σ‖中提取出具有额外条件的调节部分以中和物质手性。这个调节量被解释为σ‖的欧姆部分。结果表明，当α值较小时，纵向欧姆电导率随B的增大而增大，而当物理α = 3/4时，由于异常诱导的相互作用，纵欧姆电导率随B的增大而减小。
We calculate the electric conductivity σ in deconfined QCD matter using a holographic QCD model, i.e., the Sakai-Sugimoto Model with varying magnetic field B and chiral anomaly strength. After confirming that our estimated σ for B = 0 is consistent with the lattice-QCD results, we study the case with B 6= 0 in which the coefficient α in the Chern-Simons term controls the chiral anomaly strength. Our results imply that the transverse conductivity, σ⊥, is suppressed to be . 70% at B ∼ 1 GeV as compared to the B = 0 case when the temperature is fixed as T = 0.2 GeV. Since the Sakai-Sugimoto Model has massless fermions, the longitudinal conductivity, σ‖, with B 6= 0 should diverge due to production of the matter chirality. Yet, it is possible to extract a regulated part out from σ‖ with an extra condition to neutralize the matter chirality. This regulated quantity is interpreted as an Ohmic part of σ‖. We show that the longitudinal Ohmic conductivity increases with increasing B for small α, while it is suppressed with larger B for physical α = 3/4 due to anomaly induced interactions.