论文标题
由于金属中环电流引起的局部磁矩
Local magnetic moments due to loop currents in metals
论文作者
论文摘要
我们在一个简单的模型上介绍了Hartree-fock计算，以获得由于环电流$ L_O $和自旋环电流$ L_S $而形成局部磁矩的条件，并将它们与安德森（Anderson）相似的近似值中的局部旋转摩托车形成的条件进行了比较。一个模型，分别坐落在等边三角形上，分别在现场和最近的邻居排斥$ u $和$ v $上，以及与参数$Δ$的传导电子杂交。 $ l_o $和$ l_s $由大$ v/δ$促进，它们的幅度相对不受$ u/δ$的影响。另一方面，由大$ u/δ$推广的自旋磁矩$ m $受$ v/δ$的不利影响。在此型号中，$ l_o $ for $ v $乘以邻居的数量大致与$ u $ in Anderson的本地型号以$ m $ $ $ $ $ $ M $相同。 $ l_o $和$ l_s $如果忽略了交易所互动和洪德的规则，则是堕落的，但是$ l_o $在包括时会受到青睐。在Hartree-Fock地面状态能量的表达中，可见许多定性结果，这是小$ l_o，l_s $和$ m $的函数。为较大的值提供了Hartree-Fock能量的数值最小化。我们还简要讨论了在这里讨论的相互作用产生的轨道电流和自旋流的连接和差异，并在金属和半导体中与拓扑状态概括为晶格。
We present Hartree-Fock calculations on a simple model to obtain the conditions of formation of local magnetic moments due to loop-currents $L_o$ and spin-loop currents $L_s$ and compare them to the conditions of formation of local spin-moments $M$ which were given long ago in a similar approximation by Anderson. A model with three degenerate orbitals sitting on an equilateral triangle, with on-site and nearest-neighbor repulsions $U$ and $V$ respectively, and inter-site kinetic energy, hybridizing with conduction electrons with a parameter $Δ$ is investigated. $L_o$ and $L_s$ are promoted by large $V/Δ$ and their magnitude is relatively unaffected by $U/Δ$. Spin-magnetic moments $M$ promoted by large $U/Δ$ on the other hand are adversely affected by $V/Δ$. In this model, $L_o$ for $V$ multiplied by the number of neighbors is approximately the same as the $M$ promoted by $U$ in Anderson's local model for $M$. $L_o$ and $L_s$ are degenerate if exchange interactions and Hund's rule are neglected but $L_o$ is favored when they are included. Many of the qualitative results are visible in an expression for the Hartree-Fock ground state energy derived as a function of small $L_o, L_s$ and $M$. Numerical minimization of the Hartree-Fock energy is presented for larger values. We also briefly discuss the connection and differences of the interaction generated orbital currents and spin-currents discussed here and generalized to a lattice with the topological states in metals and semi-conductors.
