Josephson vortex lattice in layered superconductors

Abstract

Many superconducting materials are composed of weakly coupled conducting layers. Such a layered structure has a very strong influence on the properties of vortex matter in a magnetic field. This review focuses on the properties of the Josephson vortex lattice generated by the magnetic field applied in the layers direction. The theoretical description is based on the Lawrence-Doniach model in the London limit which takes into account only the phase degree of freedom of the superconducting order parameter. In spite of its simplicity, this model leads to an amazingly rich set of phenomena. We review in details the structure of an isolated vortex line as well as various properties of the vortex lattice, both in dilute and dense limits. In particular, we present an extensive consideration on the influence of the layered structure and thermal fluctuations on the selection of lattice configurations at different magnetic fields.Comment: 27 pages, 19 figures, to be published in the memorial issue of JETP devoted to A. I. Larki

Imaging Josephson Vortices on the Surface SuperconductorSi(111)−(7×3)Yoshizawa1, Kim2, Kawakami3 et al. 2014Phys. Rev. Lett.743570View full textAdd to dashboardCite

“…The vortex should be called a JV when the supercurrent distribution near the junction line is nearly parallel and the suppression ∆|Ψ center | ≡ |Ψ 0 |− |Ψ center | ≈ (J c /J 0 ) 2 |Ψ 0 | is sufficiently smaller than |Ψ 0 |. This terminology is consistent with the common usage of JVs in layered superconductors, which are created by magnetic field parallel to the layers [32,33]. [34] To compare the theoretical prediction with our experiment more directly, we numerically calculated the order parameter and the density of states (DOS) using the Bogoliubov-de Gennes (BdG) equation for a 2D tightbinding model:…”

Усиление магнитным полем собственного пиннинга в монокристалле высокотемпературного сверхпроводника TmBa-=SUB=-2-=/SUB=-Cu-=SUB=-3-=/SUB=-O-=SUB=-y-=/SUB=-

“…Вихрь, расположенный между сверхпроводящими сло-ями и имеющий свойства джозефсоновского вихря, подробно рассмотрен в обзоре [2]. Однако структура вихревого кора, если он попадет на сдвоенные сверх-проводящие CuO 2 -слои, между которыми располагает-ся магнитный слой, до сих пор не рассматривалась.…”

“…Соединения типа RBa 2 Cu 3 O y (R = Y, Ln) вблизи оп-тимального допирования имеют минимальный параметр анизотропии γ = λ c /λ ab = ξ ab /ξ c среди купратных ВТСП (γ = 5−7 [1,2]). Здесь λ ab , λ c и ξ ab , ξ c -компоненты лондоновской глубины проникновения и длины коге-рентности вдоль ab-плоскости и оси c соответствен-но.…”

Attractive interaction between superconducting vortices in tilted magnetic fields

“…Following Ref. [4], we can calculate the equilibrium distance between pancake vortices and find d ∼ 4λ ab ∼ 1µm for B || = 200 G. Using the distance between the pancake rows d rows and the value of the magnetic field B we can calculate the anisotropy factor of our BSCCO crystals γ and the distance between Josephson vortices along the c-axis, a z [1,49,50]. We obtain γ = 2d 2 rows B/( √ 3Φ 0 ) ≈ 1000 and a z ≈ 10 nm.…”