Yerin Yuriy, Drechsler Stefan-Ludwig, Cuoco Mario, Petrillo Caterina
Dipartimento di Fisica e Geologia, Universitá degli Studi di Perugia, Via Pascoli, 06123 Perugia, Italy.
CNR-SPIN, via del Fosso del Cavaliere, 100, 00133 Roma, Italy.
J Phys Condens Matter. 2023 Sep 21;35(50). doi: 10.1088/1361-648X/acf42d.
It is well-established that multicomponent superconductors can host different nonstandard phenomena such as broken-time reversal symmetry (BTRS) states, exotic Fulde-Ferrell-Larkin-Ovchinnikov phases, the fractional Josephson effect as well as plenty of topological defects like phase solitons, domain walls and unusual vortex structures. We show that in the case of a two-component superconducting quasi-one-dimensional channel this catalogue can be extended by a novel inhomogeneous current state, which we have termed as a multiple-state, characterized by the coexistence of two different interpenetrating Cooper pair condensates with different total momenta. Within the Ginzburg-Landau formalism for a dirty two-band superconductor with sizable impurity scattering treated in the Born-approximation we reveal that under certain conditions, the occurrence of multiple-states can induce a cascade of transitions involving switching between them and the homogeneous BTRS (non-BTRS) states and vice versa leading this way to a complex interplay of homogeneous and inhomogeneous current states. We find that hallmarks of such a multiple-state within a thin wire or channel can be a saw-like dependence of the depairing current and the existence of two distinct stable branches on it (a bistable current state).
多组分超导体能够呈现出不同的非标准现象,如破时间反演对称性(BTRS)态、奇异的富尔德-费雷尔-拉金-奥夫钦尼科夫相、分数约瑟夫森效应以及大量拓扑缺陷,如相孤子、畴壁和异常涡旋结构,这一点已得到充分证实。我们表明,在双组分超导准一维通道的情况下,这个现象清单可以通过一种新型的非均匀电流态得到扩展,我们将其称为多态,其特征是两种具有不同总动量的不同相互渗透的库珀对凝聚体共存。在玻恩近似下处理具有可观杂质散射的脏两带超导体的金兹堡-朗道形式体系中,我们揭示出在某些条件下,多态的出现会引发一系列转变,包括在多态与均匀BTRS(非BTRS)态之间的切换,反之亦然,从而导致均匀和非均匀电流态之间的复杂相互作用。我们发现,在细导线或通道内这种多态的标志可能是解配对电流的锯齿状依赖关系以及其上存在两个不同的稳定分支(双稳电流态)。