论文标题
在三频梯子的三波段模型中，没有路德 - emery超导阶段
Absence of Luther-Emery Superconducting Phase in the Three-Band Model for Cuprate Ladders
论文作者
论文摘要
分层层次中超导性的相关电子理论通常是从与超导状态接近的旋转液相位的前提开始的。该假设是基于掺杂的2-Leg一频哈伯德阶梯的超导路德 - emery阶段的分析和数值证明的合理性，以及耦合梯子与两个维cuO2层之间的感知类比。我们从准确的密度基质重新归一化组中证明了在掺杂的2腿三腿梯子中不存在超导的路德 - emery阶段，即使铜和氧气组成，即使自旋间隙在未悬而未决的三体梯子中很大。对于氧气原子上逼真的氧气跳和哈伯德排斥，密度密度而不是配对相关性在远距离占主导地位。该结果是否在计算中包括在梯子外和上方的梯子外部和上方的梯子外的氧气同样有效。这些结果表明了氧轨道的重要性，并提出了有关许多现有相关电子理论的超导性的不适性问题。
Correlated-electron theories of superconductivity in layered cuprates often start from the premise of a gapped spin-liquid phase proximate to the superconducting state. This assumption is justified based on analytical and numerical demonstrations of a superconducting Luther-Emery phase in the doped 2-leg one-band Hubbard ladder, and the perceived analogy between coupled ladders and the two dimensional CuO2 layer. We demonstrate from accurate density matrix renormalization group studies the absence of the superconducting Luther-Emery phase in the doped 2-leg three-band ladder consisting of both copper and oxygen, even as the spin gap is large in the undoped three-band ladder. For realistic oxygen-oxygen hopping and Hubbard repulsion on the oxygen atoms, density-density rather than pairing correlations are dominant at long range. This result is equally valid whether or not the oxygens outside the ladder proper, over and above the rung and leg oxygens, are included in the computation. These results demonstrate the critical importance of oxygen orbitals, and raise disturbing questions about the applicability of many of the existing correlated-electron theories of superconductivity.
