论文标题
与远程库仑相互作用的T-J模型中的环状电荷调制
Ring-like shaped charge modulations in the t-J model with long-range Coulomb interaction
论文作者
论文摘要
由于开发了新的，精确的X射线实验，对丘比特的电荷激发的研究目前是一个有趣的话题。基于二维$ t $ - $ j $型号的巨大$ n $公式，这使我们能够在平等的基础上考虑所有可能的充电激发，我们研究了电子和孔掺杂案例的电荷频谱。在这两种情况下，都发现具有动量调制$ {\ bf q} =（0,0）$的相位分离的不稳定性在掺杂温度相图的大区域中都很健壮。如果包括短距离库仑排斥，则相位分离区域收缩，但不稳定性保持在$ {\ bf q} =（0,0）$。另一方面，如果包括二维远程库仑交互，则包括$ {\ bf q} $ MOMMA在$ {\ bf q} =（0,0）$左右形成环的不稳定集。翻译不变相中的计算电荷光谱显示出良好的环。我们根据最近在电子和孔掺杂的丘陵中进行了X射线实验，讨论了我们的结果，其中据报道了环状形状的电荷调制。
The study of the charge excitations in cuprates is presently an interesting topic because of the development of new and precise x-ray experiments. Based on a large-$N$ formulation of the two-dimensional $t$-$J$ model, which allows us to consider all possible charge excitations on an equal footing, we investigate the charge spectrum for both electron- and hole-doped cases. In both cases, the instability toward phase separation, which has momentum modulation ${\bf q}=(0,0)$, is found to be robust in a large region of the doping-temperature phase diagram. If a short-range Coulomb repulsion is included the phase separation region shrinks, but the instability remains at ${\bf q}=(0,0)$. If on the other hand a two-dimensional long-range Coulomb interaction is included the instability sets in at ${\bf q}$ momenta forming a ring around ${\bf q}=(0,0)$. The computed charge spectrum in the translation-invariant phase shows well-formed rings. We discuss our results in the light of recent x-ray experiments in electron- and hole-doped cuprates, where ring-like shaped charge modulations have been reported.
