论文标题
电子 - 音波系统中的共鸣键状态
Resonating Valence Bond States in an Electron-Phonon System
论文作者
论文摘要
我们使用渐近的强耦合分析研究了Lieb-tate的正方形和三角形版本上的简单电子模型。 At zero temperature and electron density $n = 1$ (one electron per unit cell), for various ranges of parameters in the model, we exploit a mapping to the quantum dimer model to establish the existence of a spin-liquid phase with $\mathbb{Z}_2$ topological order (on the triangular lattice) and a multi-critical line corresponding to a quantum critical spin liquid (on the square lattice).在相图的其余部分中，我们发现了许多电荷密度波相（例如价值键晶体），一个常规的S波超导相位，以及增加了一个小的Hubbard $ u $以使余额提高余额，并具有声子诱导的D-Wave超导阶段。在特殊条件下，我们发现隐藏的伪旋转$ su（2）$对称性，这意味着对超导顺序参数的确切约束。
We study a simple electron-phonon model on square and triangular versions of the Lieb-lattice using an asymptotically exact strong coupling analysis. At zero temperature and electron density $n = 1$ (one electron per unit cell), for various ranges of parameters in the model, we exploit a mapping to the quantum dimer model to establish the existence of a spin-liquid phase with $\mathbb{Z}_2$ topological order (on the triangular lattice) and a multi-critical line corresponding to a quantum critical spin liquid (on the square lattice). In the remaining part of the phase diagram, we find a host of charge-density-wave phases (e.g. valence-bond crystals), a conventional s-wave superconducting phase, and with the addition of a small Hubbard $U$ to tip the balance, a phonon-induced d-wave superconducting phase. Under a special condition, we find a hidden pseudo-spin $SU(2)$ symmetry that implies an exact constraint on the superconducting order parameters.
