Using a separable many-body variational wavefunction, we formulate a self-consistent effective Hamiltonian theory for fermionic many-body system. The theory is applied to the two-dimensional (2D) Hubbard model as an example to demonstrate its capability and computational effectiveness. Most remarkably for the Hubbard model in 2D, a highly unconventional quadruple-fermion non-Cooper pair order parameter is discovered.

中文翻译：

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费米子多体系统的自洽有效哈密顿理论

使用可分离的多体变分波函数，我们为费米子多体系统制定了一个自洽有效的哈密顿理论。将该理论应用于二维（2D）哈伯德模型作为示例，以证明其能力和计算有效性。对于 2D 中的 Hubbard 模型，最引人注目的是发现了一个非常非常规的四重费米子非库珀对阶参数。