Linear-response dynamics from the time-dependent Gutzwiller approximation
Linear-response dynamics from the time-dependent Gutzwiller approximation
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来自时间相关 Gutzwiller 近似的线性响应动力学
DOI：
10.1088/1367-2630/15/5/053050
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发表时间：
2013
影响因子：
3.3
通讯作者：
G. Seibold
中科院分区：
文献类型：
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作者：
J. Bünemann;M. Capone;J. Lorenzana;G. Seibold
在拉格朗日形式下，我们推导了一般多带Hubbard模型的含时Gutzveler近似。我们的方法明确地结合了随时间变化的参数和随时间变化的密度矩阵之间的耦合，从这个矩阵我们得到了线性响应区域的动态关联函数。我们的结果在单带模型中得到了说明，在该模型中，相互作用系统可以被映射为费米子准粒子与双占据玻色子涨落耦合的有效问题。后者在稀度极限下具有相当于现场Hubbard排斥U的能量，但在布林克曼-赖斯转变时能量变软，这与一个新出现的双子电荷守恒定律和相应的规范不变性有关。与玻色子模的耦合在电荷响应中产生了一个结构，我们发现在动力学平均场理论中也出现了类似的结构。
Within a Lagrangian formalism, we derive the time-dependent Gutzwiller approximation for general multi-band Hubbard models. Our approach explicitly incorporates the coupling between time-dependent variational parameters and a time-dependent density matrix from which we obtain dynamical correlation functions in the linear-response regime. Our results are illustrated for the one-band model where we show that the interacting system can be mapped to an effective problem of fermionic quasiparticles coupled to'doublon'(double occupancy) bosonic fluctuations. The latter have an energy on the scale of the on-site Hubbard repulsion U in the dilute limit but become soft at the Brinkman–Rice transition, which is shown to be related to an emerging conservation law of doublon charge and the associated gauge invariance. Coupling with the boson mode produces a structure in the charge response and we find that a similar structure appears in dynamical mean-field theory.
多体特征值谱中的动态量子相变和对称破缺边
DOI：
--
发表时间：
2012
期刊：
影响因子：
--
作者：
G. Mazza;M. Fabrizio
通讯作者：
M. Fabrizio