Krumnow C, Veis L, Legeza Ö, Eisert J
Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, 14195 Berlin, Germany.
Strongly Correlated Systems "Lendület" Research Group, Wigner Research Centre for Physics, Hungarian Academy of Sciences, 1525 Budapest, Hungary.
Phys Rev Lett. 2016 Nov 18;117(21):210402. doi: 10.1103/PhysRevLett.117.210402.
Tensor network states and specifically matrix-product states have proven to be a powerful tool for simulating ground states of strongly correlated spin models. Recently, they have also been applied to interacting fermionic problems, specifically in the context of quantum chemistry. A new freedom arising in such nonlocal fermionic systems is the choice of orbitals, it being far from clear what choice of fermionic orbitals to make. In this Letter, we propose a way to overcome this challenge. We suggest a method intertwining the optimization over matrix product states with suitable fermionic Gaussian mode transformations. The described algorithm generalizes basis changes in the spirit of the Hartree-Fock method to matrix-product states, and provides a black box tool for basis optimization in tensor network methods.
张量网络态，特别是矩阵乘积态，已被证明是模拟强关联自旋模型基态的有力工具。最近，它们也被应用于相互作用费米子问题，特别是在量子化学的背景下。在这种非局部费米子系统中出现的一个新的自由度是轨道的选择，而选择什么样的费米子轨道远不清楚。在本信函中，我们提出了一种克服这一挑战的方法。我们建议一种将矩阵乘积态的优化与合适的费米子高斯模式变换相结合的方法。所描述的算法将哈特里 - 福克方法精神下的基变换推广到矩阵乘积态，并为张量网络方法中的基优化提供了一个黑箱工具。
