The profiles of local density of states (LDOS) around different vortex configurations in mesoscopic superconductors are studied taking account of the interference of quasiparticle waves experiencing Andreev reflection within the vortex cores and normal reflection at the boundaries or defects. For subgap energy levels these interference effects reveal themselves in a nontrivial dependence of the positions of the LDOS peaks on the intervortex distance and sample size: the peak positions generally do not coincide with the superconducting phase singularity points. The LDOS profiles are calculated for three generic examples: (i) vortex-vortex pair; (ii) vortex positioned near a flat boundary; (iii) vortex positioned in the center of a superconducting disk. The resulting evolution of the Andreev interference patterns could be observable by scanning tunneling spectroscopy techniques.
We present theoretical and numerical investigations of vortices driven by strong dc and ac currents in long Josephson junctions described by a nonlinear integro-differential equation which takes into account nonlocal electrodynamics of films, vortex bremsstrahlung and Cherenkov radiation amplified by the attraction of vortices to the edges of the junction. The work focuses on the dynamics of vortices in Josephson junctions in thin films where the effects of Josephson nonlocality dominate but London screening is negligible. We obtained an exact solution for a vortex driven by an arbitrary time-…
Braiding Majorana zero modes is essential for fault-tolerant topological quantum computing. Iron-based superconductors with nontrivial band topology have recently emerged as a surprisingly promising platform for creating distinct Majorana zero modes in magnetic vortices in a single material and at relatively high temperatures. The magnetic field-induced Abrikosov vortex lattice makes it difficult to braid a set of Majorana zero modes or to study the coupling of a Majorana doublet due to overlapping wave functions. Here we report the observation of the proposed quantum anomalous vortex with int…
Strains in superconductors due to moving vortices and vortex lattices are discussed. It is shown that the energy stored in elastic strains increases with vortex velocity. For moving vortex lattices, the elastic energy depends on velocity orientation relative to the lattice having minimum for the velocity directed along one of the unit cell vectors of the moving lattice. It is shown that for supersonic motion, the vortex induced stress field has a shape similar to supersonic shock waves.
We have investigated vortex states in chiral helimagnet/superconductor bilayer systems under an applied external magnetic field Happl, using the Ginzburg-Landau equations. Effect of the chiral helimagnet on the superconductor is taken as a magnetic field HCHM, which is perpendicular to the superconductor and oscillates spatially. For Happl = 0 and weak HCHM, there appear pairs of up-and down-vortices. Increasing Happl, down-vortices gradually disappear, and number of up-vortices increases in the large magnetic field region. Then, up-vortices form parallel, triangular, or square structures.
We use large-scale Monte-Carlo simulations to study thermal fluctuations in chiral $p$-wave superconductors in an applied magnetic field in three dimensions. We consider the thermal stability of previously predicted unusual double-quanta flux-line lattice ground states in such superconductors. In previous works it was shown that, neglecting thermal fluctuations, a chiral $p$-wave superconductor forms an hexagonal lattice of doubly-quantized vortices, except extremely close to the vicinity of $H_{c2}$ where double-quanta vortices split apart. We find dissociation of double-quanta vortices drive…
The magnetic field $h_z$ of a moving Pearl vortex in a superconducting thin-film in $(x,y)$ plane is studied with the help of time-dependent London equation. It is found that for a vortex at the origin moving in $+x$ direction, $h_z(x,y)$ is suppressed in front of the vortex, $x>0$, and enhanced behind ($x<0$). The distribution asymmetry is proportional to the velocity and to the conductivity of normal quasiparticles. The vortex self-energy and the interaction of two moving vortices are evaluated.
Emergence of Spin-Half Fermion Vortices and The Vortex Metal
这篇论文已被撤回，取而代之的是一个新的版本，题为“二维格点玻色子的涡旋量子动力学”由Netanel H。Lindner，Assa Auerbach，Daniel P. Arovas，posted in arXiv：0810.2604.原始手稿的计算和结果是正确的，并导致了几个重要的结论，涡旋动力学和霍尔电导。然而，我们已经放弃了我们的猜想，即涡旋表现出相互费米统计。该猜想是基于16格点环形晶格的最低八个多体本征态所揭示的两个涡旋交换下的反对称性。诉诸更大晶格上的有效哈珀玻色子模型，揭示了具有玻色和费米置换对称性的涡旋本征态，尽管涡旋确实携带半个量子数的自旋。这可能意味着，在二维空间中，一般的非相对论性“自旋统计定理”并不成立。
Fluctuating pancake vortices revealed by dissipation of Josephson vortex lattice
在倾斜磁场中的强各向异性层状超导体中，约瑟夫森涡旋晶格与饼状涡旋晶格共存。由于它们之间的相互作用，约瑟夫森涡晶格的耗散发生是非常敏感的煎饼涡的存在。如果c轴磁场小于相应的低临界场，则不会形成饼状堆叠，但单个饼状可能存在于波动制度中，或者在大尺寸样品的表面附近，或者在小尺寸台面的中心区域。我们计算的贡献，这种波动的煎饼涡的约瑟夫森涡晶格的c-轴电导率，并比较的理论结果与小台面制作出的Bi $_{2}$锶$_{2}$钙铜$_{2}$ O $_{8+δ}$晶体的测量。波动煎饼的指纹是实验观察到的c轴电导率的特征指数依赖性。我们的研究结果提供了强有力的证据的波动煎饼的存在及其对约瑟夫森涡晶格耗散的影响。
Molecular Dynamics of pancake vortices with realistic interactions: Observing the vortex lattice melting transition
在本文中，我们描述了一个版本的伦敦朗之万分子动力学模拟，允许在高度各向异性的高温超导体材料Bi $_2$ Sr $_2$ CaCu $_2$ O $_{8+δ}$的涡旋晶格熔化转变的调查。我们考虑了饼状涡之间的完全电磁相互作用和约瑟夫森相互作用。我们还在所有方向上实施周期性边界条件，包括沿其施加磁场的z轴。我们将展示如何实现通量切割和重连作为一个模拟的排列在多级Monte Carlo方案，并证明这一过程导致磁通纠缠扩散的涡旋液相。观察到的涡旋晶格的一阶熔化转变与以前的多级蒙特卡罗模拟非常一致。
Superconducting materials with noncentrosymmetric lattices lacking space inversion symmetry exhibit a variety of interesting parity-breaking phenomena, including the magneto-electric effect, spin-polarized currents, helical states, and the unusual Josephson effect. We demonstrate, within a Ginzburg-Landau framework describing noncentrosymmetric superconductors with $O$ point group symmetry, that vortices can exhibit an inversion of the magnetic field at a certain distance from the vortex core. In stark contrast to conventional superconducting vortices, the magnetic-field reversal in the parity…
本文提出了一个中子星壳内中子涡旋的微观量子力学模型。在简要介绍了Bogoliubov- de Gennes方程，这是我们的计算的基础上，我们提出的结果的密度分布，涡核的大小和涡能量，无论是一个孤立的中子涡和涡核重叠的情况下，与一个圆柱形核。证实了涡核尺寸的早期结果，表明涡核尺寸随密度的变化比BCS公式预测的要小得多。
We investigate the effects related to vortex core deformations when vortices approach each other. As a result of these vortex core deformations, the vortex-vortex interaction effectively acquires an attractive component leading to a variety of vortex patterns typical for systems with non-monotonic repulsive-attractive interaction, such as stripes, labyrinths, etc. The core deformations are anisotropic and can induce frustration in the vortex-vortex interaction. In turn, this frustration has an impact on the resulting vortex patterns, which are analyzed in the presence of additional random pinn…
We present the analysis of the structure of fermionic vortices with the spin-polarized core from a weak coupling limit to the unitary regime. We show the mechanism for the generation of the {\it reversed circulation} in the vortex core induced by an excess of majority spin particles. We introduce the classification of the polarized vortices based on the number of Fermi circles where the minigap vanishes. This provides a unique description of the vortex as one cannot smoothly map wave functions into one another corresponding to vortices differing by the number of Fermi circles. The effective ma…
We study quantized vortices in ${}^{3}P_{2}$ superfluids using a microscopic theory for the first time. The theory is based on the Eilenberger equation to determine the order parameters and the Bogoliubov-de Gennes (BdG) equation to obtain the eigenenergies and the core magnetization. Within axisymmetric vortex configurations, we find several stable and metastable vortex configurations which depend on the strength of a magnetic field, similar to a $v$ vortex and $o$ vortex in $^3$He superfluids. We demonstrate that the $o$ vortex is the most stable axisymmetric vortex in the presence of a stro…
