Self-consistent dual boson approach to single-particle and collective excitations in correlated systems
Self-consistent dual boson approach to single-particle and collective excitations in correlated systems
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相关系统中单粒子和集体激发的自洽双玻色子方法
DOI：
10.1103/physrevb.93.045107
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发表时间：
2015
影响因子：
3.7
通讯作者：
A. N. Rubtsov
中科院分区：
文献类型：
--
作者：
E. Stepanov;E. V. Loon;A. Katanin;A. Lichtenstein;M. Katsnelson;A. N. Rubtsov
我们提出了一个有效的双玻色子计划，它扩展了DMFT范式的集体激发相关系统。该理论在单粒子和双粒子水平上都是完全自洽的，从而描述了集体模式的形成以及电子和玻色子光谱的重正化。该方法采用了一个有效的杂质模型，包括费米子和玻色子杂化功能。由于有效玻色浴的自洽条件的最优选择，只有参考问题的单电子和双电子绿色函数进入理论。我们表明，该理论是自然描述的对偶Luttinger-Ward功能，并遵守相关的守恒律。
We propose an efficient dual boson scheme, which extends the DMFT paradigm to collective excitations in correlated systems. The theory is fully self-consistent both on the one- and on the two-particle level, thus describing the formation of collective modes as well as the renormalization of electronic and bosonic spectra on equal footing. The method employs an effective impurity model comprising both fermionic and bosonic hybridization functions. Only single- and two-electron Green's functions of the reference problem enter the theory, due to the optimal choice of the self-consistency condition for the effective bosonic bath. We show that the theory is naturally described by a dual Luttinger-Ward functional and obeys the relevant conservation laws.