论文标题
费米昂边界状态保留了哪些对称性？
What Symmetries are Preserved by a Fermion Boundary State?
论文作者
论文摘要
通常，d = 1+1的尺寸中的左移动费用反映了边界，以成为右移动的费米昂。这意味着，虽然总体费米亚奇偶校验$（-1）^f $是保守的，但左和右手的手性费米昂均等却不是。值得注意的是，有一些边界条件确实保留了手性费米昂的奇偶校验，但是只有当Majorana fermions的数量是8的倍数时。只有在$ 2n $被8 $可将$ 2N $排除的情况下，手性赋予 - 帕元的边界条件就会存在。我们还对这种边界状态保留的增强的连续对称性进行了分类。这种对称性最大的状态是$ SO（8）$边界状态，首先由Maldacena和Ludwig构建，以描述Fermions在单极管上的散射
Usually, a left-moving fermion in d=1+1 dimensions reflects off a boundary to become a right-moving fermion. This means that, while overall fermion parity $(-1)^F$ is conserved, chiral fermion parity for left- and right-movers individually is not. Remarkably, there are boundary conditions that do preserve chiral fermion parity, but only when the number of Majorana fermions is a multiple of 8. In this paper we classify all such boundary states for $2N$ Majorana fermions when a $U(1)^N$ symmetry is also preserved. The fact that chiral-parity-preserving boundary conditions only exist when $2N$ is divisible by 8 translates to an interesting property of charge lattices. We also classify the enhanced continuous symmetry preserved by such boundary states. The state with the maximum such symmetry is the $SO(8)$ boundary state, first constructed by Maldacena and Ludwig to describe the scattering of fermions off a monopole
