非均匀磁相：Sr3Ru2O7中的类LOFF相

具有非齐次相互作用的吸引哈伯德模型的Phase Diagram

Phase Diagram of the Attractive Hubbard Model with Inhomogeneous Interactions

利用单格位动力学平均场论方法，得到了具有空间非均匀相互作用的吸引哈伯德模型的相图。该模型的特点是由三个参数：相互作用强度，活性分数（分数的网站与吸引力的相互作用），和电子填充。计算表明，在一个参数制度与中间值的相互作用强度（相比，裸露的带宽的电子），和中间值的活性分数，“非BCS”的超导电性得到。这项工作的结果可能是相关的许多系统与空间非均匀超导性，如强关联氧化物，系统与负U中心，并在未来，冷原子光晶格。

二维阻挫相分离中的非均匀态

Inhomogeneous states in two-dimensional frustrated phase separation

本文导出了具有负短程电子压缩性的二维系统中库仑阻挫相分离范例模型的相图。我们考虑系统的真实三维长程库仑相互作用（LRC）和二维LRC与类牛顿力学行为。在这两种情况下，我们发现，从均匀相到非均匀相的过渡一般是一阶除了临界点。接近临界点，不均匀性安排在一个三角形晶格与随后的一阶拓扑过渡到条纹状物体，降低库仑挫折。扩散的内部较小的不均匀性的不均匀性，预计在所有的过渡线的系统中嵌入的三维LRC单独。

Hump-like structure in Hall signal from SrRuO$_3$ ultra-thin films without inhomogeneous anomalous Hall effect

A controversy arose over the interpretation of the recently observed hump features in Hall resistivity $ρ_{xy}$ from ultra-thin SrRuO$_3$ (SRO) film; it was initially interpreted to be due to topological Hall effect but was later proposed to be from existence of regions with different anomalous Hall effect (AHE). In order to settle down the issue, we performed Hall effect as well as magneto-optic Kerr-effect measurements on 4 unit cell SRO films grown on SrTiO$_3$ (001) substrates. Clear hump features are observed in the measured $ρ_{xy}$, whereas neither hump feature nor double hysteresis loo…

非均匀哈伯德模型中的超导电性

Superconductivity in Inhomogeneous Hubbard Models

我们提出了一种控制微扰方法来计算团簇间小耦合$t'$极限下的高度非均匀哈伯德模型的低温相图。我们将其应用于二聚和棋盘模型。发现二聚化模型的行为类似于杂质半导体，具有费米液体基态，其参数为（{ \it例如}）。有效质量），它们是哈伯德相互作用$U$的光滑函数。相比之下，棋盘模型中$0 < U < U_c$的d波超导态是无节点的（预制对凝聚态，$d$ -BEC），而$|U - U_c| < {\cal O}(t^\prime)$的d波超导态则平滑地过渡到类似BCS的中间超导相（$d$ -BCS），同样没有节点准粒子，而$U > U_c = 4.58$的d波超导相则是费米液相。

Collective magnetic response of inhomogeneous nanoisland FeNi films around the percolation transition

By using superconducting quantum interference device (SQUID) magnetometry we investigated anisotropic high-field (H < 7 T) low-temperature (10 K) magnetization response of inhomogeneous nanoisland FeNi films grown by rf sputtering deposition on Sitall (TiO2) glass substrates. In the grown FeNi films, the FeNi layer nominal thickness varied from 0.6 to 2.5 nm, across the percolation transition at the d_c=1.8 nm. We discovered that, beyond conventional spin-magnetism of Fe21Ni79 permalloy, the extracted out-of-plane magnetization response of the nanoisland FeNi films is not saturated in the rang…