论文标题
多摩德金属间系统上表现出竞争订单的多型金属间系统上的不相关的电荷密度波
Incommensurate charge density wave on multiband intermetallic systems exhibiting competing orders
论文作者
论文摘要
在多台上的金属间系统上呈现相应的电荷密度波(CDW)和超导性(SC)订单的多型金属间系统上的不超量电荷密度波矢量$ \ textbf {q} =(q_x,q_y)$的外观。我们考虑在平方晶格中的两种频段模型,其中带有不同的有效质量。不稳定的CDW(INCDW)和CDW相源于频带间的库仑排斥性相互作用,而SC由于局部内部的有吸引力的相互作用而出现。为简单起见,所有交互,频段之间的顺序参数和杂交都被认为$ \ textbf {k} $ - 独立。我们感兴趣的多机系统是金属间系统,具有$ d $ band与大型$ c $ band共存的金属系统,事实证明,均值场上的方法是合适的。我们从数值上获得了汉密尔顿的特征值和特征向量,并通过Hellmann-Feynman定理对模型的不同参数最小化自由能密度。我们在实际和动量空间中调查了系统,并找到了带有波矢量$ \ textbf {q} =(π,q_y)=(q_x,π)$的INCDW阶段。我们的数值结果表明,INCDW状态的产生取决于参数,例如INCDW和CDW相互作用的大小,带填充,杂交和频带的相对深度。通常,INCDW倾向于在低温下出现,远离半填充。我们还表明,CDW排序是相应的还是不相称的,频段之间相对深度的巨大值可能会抑制它。我们讨论模型的每个参数如何影响INCDW阶段的出现。
The appearance of an incommensurate charge density wave vector $\textbf{Q} = (Q_x,Q_y)$ on multiband intermetallic systems presenting commensurate charge density wave (CDW) and superconductivity (SC) orders is investigated. We consider a two-band model in a square lattice, where the bands have distinct effective masses. The incommensurate CDW (inCDW) and CDW phases arise from an interband Coulomb repulsive interaction, while the SC emerges due to a local intraband attractive interaction. For simplicity, all the interactions, the order parameters and hybridization between bands are considered $\textbf{k}$-independent. The multiband systems that we are interested are intermetallic systems with a $d$-band coexisting with a large $c$-band, for which a mean-field approach has proved suitable. We obtain the eigenvalues and eigenvectors of the Hamiltonian numerically and minimize the free energy density with respect to the diverse parameters of the model by means of the Hellmann-Feynman theorem. We investigate the system in real as well as momentum space and we find an inCDW phase with wave vector $\textbf{Q} = (π, Q_y) = (Q_x, π)$. Our numerical results show that the arising of an inCDW state depends on parameters, such as the magnitude of the inCDW and CDW interactions, band filling, hybridization and the relative depth of the bands. In general, inCDW tends to emerge at low temperatures, away from half-filling. We also show that, whether the CDW ordering is commensurate or incommensurate, large values of the relative depth between bands may suppress it. We discuss how each parameter of the model affects the emergence of an inCDW phase.