1. Implementing the density matrix embedding theory with the hierarchical mean-field approach.
- Author
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Qin, Jingbo, Jie, Quanlin, and Fan, Zhuo
- Subjects
- *
DENSITY matrices , *EMBEDDING theorems , *MEAN field theory , *LATTICE dynamics , *QUANTUM spin models , *HEISENBERG model , *QUANTUM phase transitions - Abstract
We show an implementation of density matrix embedding theory (DMET) for the spin lattice of infinite size. It is indeed a special form of hierarchical mean-field (HMF) theory. In the method, we divide the lattice into a small part and a large part. View the small part as an impurity, embedding in the large part, which is viewed as the environment. We deal the impurity with a high accuracy method. But treat the environment with a low-level method: the states of the environment nearby the impurity are expressed by a set of multiple block product states, while the distant parts are treated by mean-field consideration. Our method allows for the computation of the ground state of the infinite two-dimensional quantum spin systems. In the text, we take the frustrated Heisenberg model as an example to test our method. The ground state energy we calculated can reach a high accuracy. We also calculate the magnetization, and the fidelity to study the quantum phase transitions. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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