Making trotters sprint: A variational imaginary time ansatz for quantum many-body systems
Making trotters sprint: A variational imaginary time ansatz for quantum many-body systems
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DOI：
10.1103/physrevb.100.094434
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发表时间：
2019-09-20
影响因子：
3.7
通讯作者：
Hsieh, Timothy H.
中科院分区：
文献类型：
--
作者：
Beach, Matthew J. S.;Melko, Roger G.;Hsieh, Timothy H.
我们引入了一个变分波函数的多体基态，涉及到两个不同的哈密顿量在一个交替的方式与可变的时间间隔的时间演化。我们成功地将该方法应用到一维和二维横场伊辛模型中，并系统地研究了临界态下一维模型的标度性。我们发现总虚时间所需的尺度与系统的大小，在传统的量子Monte Carlo的线性标度。我们认为这是由于交替的时空演化所允许的独特动力学，包括指数增长的二分纠缠。对于通用模型，我们的ananterior的上级缩放可能减轻了负号问题的代价，必须优化变分参数。
We introduce a variational wave function for many-body ground states that involves imaginary-time evolution with two different Hamiltonians in an alternating fashion with variable time intervals. We successfully apply the ansatz on the one- and two-dimensional transverse-field Ising model and systematically study its scaling for the one-dimensional model at criticality. We find the total imaginary time required scales logarithmically with system size, in contrast to the linear scaling in conventional quantum Monte Carlo. We suggest this is due to unique dynamics permitted by alternating imaginary-time evolution, including exponential growth of bipartite entanglement. For generic models, the superior scaling of our ansatz potentially mitigates the negative sign problem at the expense of having to optimize variational parameters.