A holographic model for quantum critical responses
A holographic model for quantum critical responses
复制标题
DOI：
10.1007/jhep05(2016)073
复制
发表时间：
2016-05
影响因子：
5.4
通讯作者：
R. Myers;T. Sierens;W. Witczak-Krempa
中科院分区：
文献类型：
--
作者：
R. Myers;T. Sierens;W. Witczak-Krempa
我们分析了共形场论描述的强相互作用量子临界态的动力学响应函数。我们构造了一个自洽的全息模型，它包含了驱动量子临界相变的相关标量算符。针对有限温度动力学电导率σ（ω，T），研究了它与模型参数的关系，特别是与相关算子的标度维数的关系.结果表明，在较宽的参数范围内，电导率可以用文献[1]中提出的一个简单的近似公式来近似。我们进一步使用算子乘积展开来剖析大频率ω <$T下的电导率，并展示它如何揭示我们的模型CFT的频谱。我们的结果提供了一个物理约束的框架来研究量子Monte Carlo数据的解析延拓，正如我们使用O（2）Wilson-Fisher CFT所说明的那样。最后，我们评论的电导率的变化，因为我们调谐远离量子临界点，设置的过渡附近的相图的全面分析阶段。
We analyze the dynamical response functions of strongly interacting quantum critical states described by conformal field theories (CFTs). We construct a self-consistent holographic model that incorporates the relevant scalar operator driving the quantum critical phase transition. Focusing on the finite temperature dynamical conductivity σ (ω, T), we study its dependence on our model parameters, notably the scaling dimension of the relevant operator. It is found that the conductivity is well-approximated by a simple ansatz proposed in [1] for a wide range of parameters. We further dissect the conductivity at large frequencies ω≫ T using the operator product expansion, and show how it reveals the spectrum of our model CFT. Our results provide a physically-constrained framework to study the analytic continuation of quantum Monte Carlo data, as we illustrate using the O (2) Wilson-Fisher CFT. Finally, we comment on the variation of the conductivity as we tune away from the quantum critical point, setting the stage for a comprehensive analysis of the phase diagram near the transition.