Local magnetization hysteresis is among the most extensively studied features of high-temperature superconductors (HTSC). The usual source of hysteresis in superconductors is bulk vortex pinning due to material defects. Two additional known mechanisms of magnetic irreversibility are the Bean-Livingston surface barrier and the geometrical barrier (GB). GB arises due to a competition between the line energy of a vortex penetrating into the sample and the Lorentz force of Meissner currents which focuses vortices in the sample's center to form a dome-shaped vortex distribution. This work demonstrates that dc in-plane field overcomes hysteresis mainly through the GB suppression in a region of phase diagram under consideration (high temperatures and low fields).
Field-induced suppression of the pi-band superconductivity and magnetic hysteresis in the microwave surface resistance of MgB_2 at temperatures near T_c
Onset of superconductivity and hysteresis in magnetic field for a long cylinder as obtained from a self-consistent solutions of the Ginzburg--Landau equations
Microscopic Derivation of Magnetic Flux Density Profiles, Magnetization Hysteresis Loops, and Critical Currents in Strongly Pinned Superconductors
我们提出了一个微观的推导，没有电动力学的假设，$B(x,y,H(t))$，$M(H(t))$，和$J_c(H(t))$，与实验一致的强钉扎超导体，钉扎位点的密度和强度的值的范围。我们数值求解了这些磁通梯度驱动的涡的过阻尼运动方程，这些涡可以暂时被困在钉扎中心。通过在样品边界处添加（去除）磁通线来增加（减少）磁场，并且通过使用具有相反取向的磁通线可以实现完整的磁滞回线。对于强钉扎涡，我们得到的单位体积钉扎力$J_c B \sim n_p f_p^{1.6}$介于以下两种极端情况之间：非常强钉扎的独立涡，其中$J_c B \sim n_p f_p$，以及弱钉扎直涡的二维Larkin-Ovchinikov集体钉扎理论，其中$J_c B \sim n_p f_p^{2}$。这里，$n_p$和$f_p$是钉扎位点的密度和最大力。
Suppression of magnetic order in CaCo$_{1.86}$As$_{2}$ with Fe substitution: Magnetization, neutron diffraction, and x-ray diffraction studies of Ca(Co$_{1-x}$Fe$_{x}$)$_{y}$As$_{2}$
磁化，中子衍射，高能X射线衍射结果的Sn助熔剂生长的单晶样品的Ca（Co $_{1-x}$ Fe $_{x}$）$_{y}$作为$_{2}$，$0\leq x\leq1$，$1.86\leq y \leq 2$，并显示A型反铁磁秩序，与有序的时刻位于沿$c$轴，持续为$x\lesssim0.12(1)$。随着$x$的增加，反铁磁序被平滑地抑制，有序矩和Néel温度都线性降低。$x\leq0.25$不出现条纹型反铁磁序，$x$也不出现铁磁序，至少达到$x=0.104$，并且发生从CaCo $_{1.86}$ As $_{2}$的四重（cT）相到CaFe $_{2}$ As $_{2}$的四重（T）相的平滑交叉。这些结果表明，空穴掺杂CaCo $_{1.86}$ As $_{2}$对磁性和结构的影响不如Sr取代Ca的空间效应显著。
