论文标题
库珀对环模型
Cooper pair ring model
论文作者
论文摘要
当外部施加的磁场超过Meissner-Ochsenfeld临界场时，超导状态开始崩溃，BC，MO中的Meissner-ochsenfeld临界场是II II超导导体，而在I型II超导体中，该领域是较低的临界场。在这里我们表明，这两个关键字段都可以通过$ b $$ _ {c，mo} $ = $ = $ = $μ$ _ 0 $ n $ n $ n $ n $ n $ $ $ $ $ $ $ $ $ $ $ $ _ b $$ ln（1+2 $ 2 $^{0.5} $ $ $μ$$ _ b $是Bohr Magneton，$κ$是Ginzburg-Landau参数。结果，Meissner-Ochsenfeld场可以定义为每个库珀对具有$ ln的多重pretalter（1+2 $^{0.5} $$κ$）的bohr magneton的磁磁矩。在二维情况下，这意味着库珀对质量中心在空间上限制在一个半径$ $ξ$和$ξ$+2 $+2 $^{0.5} $$λ$的环内，其中$ξ$是连贯的长度，$λ$是伦敦穿透性深度。这意味着超导转变不仅与电荷载体配对有关，而且对带有1属的新拓扑状态。
The superconducting state starts to collapse when the externally applied magnetic field exceeds the Meissner-Ochsenfeld critical field, Bc,MO, which in type-I superconductors is the thermodynamic critical field, while in type-II superconductors this field is the lower critical field. Here we show that both critical fields can be described by the universal equation of $B$$_{c,MO}$=$μ$$_0$$n$$μ$$_B$$ln(1+2$$^{0.5}$$κ$), where $μ$$_0$ is the magnetic permeability of free space, $n$ is the Cooper pairs density, and $μ$$_B$ is the Bohr magneton, and $κ$ is the Ginzburg-Landau parameter. As a result, the Meissner-Ochsenfeld field can be defined as the field at which each Cooper pair exhibits the diamagnetic moment of one Bohr magneton with a multiplicative pre-factor of $ln(1+2$$^{0.5}$$κ$). In the two-dimensional case this implies that the Cooper pair center of mass is spatially confined within a ring with inner radius $ξ$ and outer radius of $ξ$+2$^{0.5}$$λ$, where $ξ$ is the coherence length and $λ$ is the London penetration depth. This means that the superconducting transition is associated not only with the charge carrier pairing, but that the pairs exhibit a new topological state with genus 1.
