论文标题
交换潜在形式主义中半填充1D哈伯德链的光谱函数
Spectral functions of the half-filled 1D Hubbard chain within the exchange-correlation potential formalism
论文作者
论文摘要
一频的半填充1D哈伯德链的光谱函数是使用最近开发的交换相关潜在形式主义计算的。交换相关电位是从哈伯德二聚体得出的确切电势中采用的。在完整的绿色函数被非相互作用替代的近似值中，可以通过分析计算光谱函数。尽管近似值很简单，但所产生的光谱与从动态密度 - 矩阵重生组方法获得的更准确的结果相吻合。特别是，计算出的带隙随$ u $的函数与从贝特·安萨兹（Bethe Ansatz）获得的确切差距达成了密切的一致性。此外，还提出了绿色功能运动方程的正式一般解决方案，并还讨论和详细介绍了传统的自能力方法与交换相关潜在形式主义之间的差异。简化的荷斯坦汉密尔顿人被认为进一步说明了交换相关潜力的一般形式。
The spectral functions of the one-band half-filled 1D Hubbard chain are calculated using the exchange-correlation potential formalism developed recently. The exchange-correlation potential is adopted from the exact potential derived from the Hubbard dimer. Within an approximation in which the full Green function is replaced by a non-interacting one, the spectral functions can be calculated analytically. Despite the simplicity of the approximation, the resulting spectra are in favorable agreement with the more accurate results obtained from the dynamic density-matrix renormalization group method. In particular, the calculated band gap as a function of $U$ is in close agreement with the exact gap obtained from the Bethe ansatz. In addition, the formal general solution to the equation of motion of the Green function is presented and the difference between the traditional self-energy approach and the exchange-correlation potential formalism is also discussed and elaborated. A simplified Holstein Hamiltonian is considered to further illustrate the general form of the exchange-correlation potential.
