Vielbein with mixed dimensions and gravitational global monopole in the planar phase of superfluid $^3$He

From elasticity tetrads to rectangular vielbein

The paper is devoted to the memory of Igor E. Dzyaloshinsky. In our common paper I.E. Dzyaloshinskii and G.E. Volovick, Poisson brackets in condensed matter, Ann. Phys. {\bf 125} 67--97 (1980), we discussed the elasticity theory described in terms of the gravitational field variables -- the elasticity vielbein $E_μ^a$. They come from the phase fields, which describe the deformations of crystal. The important property of the elasticity vielbein $E^a_μ$ is that in general they are not the square mstrices. While the spacetime index $μ$ takes the values $μ=(0,1,2,3)$, in crystals the index $a=(1,2…

彩色超导体界面上的彩色boojums

Colorful boojums at the interface of a color superconductor

我们研究的漩涡，或boojums，在颜色和强子超导/超流相之间的接口。这种类型的界面可能存在于中子星的内部，其中由色香味锁相的夸克物质组成的内核被超导质子和超流中子的外壳包围。我们研究的命运磁（质子）和超流体（中子）漩涡，因为他们进入的颜色-味道锁定阶段。我们发现质子涡旋终止于无质量磁场的狄拉克磁单极子上，而有质量规范场的磁通量沿表面传播并被表面超导电流屏蔽。另一方面，三个中子涡旋在一个boojum处汇合并分裂成三个色磁涡旋，当考虑奇异夸克质量时，这些色磁涡旋具有受限的色磁单极子。我们还提出了一个简单的数值模型的形状的中子boojum。

Emergence of non-abelian magnetic monopoles in a quantum impurity problem

Recently it was shown that molecules rotating in superfluid helium can be described in terms of the angulon quasiparticles (Phys. Rev. Lett. 118, 095301 (2017)). Here we demonstrate that in the experimentally realized regime the angulon can be seen as a point charge on a 2-sphere interacting with a gauge field of a non-abelian magnetic monopole. Unlike in several other settings, the gauge fields of the angulon problem emerge in the real coordinate space, as opposed to the momentum space or some effective parameter space. Furthermore, we find a topological transition associated with making the …

超流费米气体集体模中的温度和有限尺寸效应

Temperature and finite-size effects in collective modes of superfluid Fermi gases

研究了超流性对原子间相互作用下稀薄超冷费米气体的四极和四极集体激发的影响。该系统的Bogoliubov-德Gennes和准粒子随机相位近似方法内完全微观处理。温度和陷阱频率的依赖关系进行了分析，并与相应的流体动力学预测系统的比较，以研究的半经典方法的有效性的限制。

Composite topological objects in topological superfluids

Superfluid phases of $^3$He discovered in 1972 opened the new area of the application of topological methods to condensed matter systems. Due to the multi-component order parameter which characterizes the broken $SO(3)\times SO(3)\times U(1)$ symmetry in these phases, there are many inhomogeneous objects -- textures and defects in the order parameter field -- which are protected by topology and are characterized by topological quantum numbers. Among them there are quantized vortices, skyrmions and merons, solitons and vortex sheets, monopoles and boojums, Alice strings, Kibble-Lazarides-Shafi …

超流体中的Andreev-Majorana束缚态

Andreev-Majorana bound states in superfluids

本文研究了$p$波超流体的表面、界面和涡旋上的零能量Andreev-Majorana（AM）束缚态。我们讨论了手征超流$^3$ He-A，和时间反演不变相：超流$^3$ He-B，平面相和极性相。AM零模是由体拓扑决定的，它们在超流体从拓扑态到非拓扑态的量子相变时消失。拓扑展示了维度的相互作用。特别地，手征超流体中的零维Weyl点（动量空间中的Berry相单极）在表面上产生AM束缚态的一维费米弧，在涡核中产生AM模的一维平坦带。极性相的一维节线在表面产生二维的AM模平带。维度的相互作用也将不同维度的超流体中的AM态联系起来。例如，三维$^3$ He-B中的束缚态谱的拓扑性质与二维平面相（薄膜）中的谱的性质相关联。