Current distribution and transition width in superconducting transition-edge sensors
Current distribution and transition width in superconducting transition-edge sensors
复制标题
超导过渡边缘传感器中的电流分布和过渡宽度
DOI：
10.1063/1.4771984
复制
发表时间：
2012
影响因子：
4
通讯作者：
J. Ullom
中科院分区：
文献类型：
--
作者：
D. Swetz;D. Bennett;K. Irwin;D. Schmidt;J. Ullom
过渡边缘传感器（TES）中的超导到正常过渡的现有模型不描述偏置TES内的电流分布。这种分布是复杂的正常金属功能，是不可分割的TES设计。我们提出了一个模型，一个自由参数，描述了偏置的电流分布的演变。为了探测电流分布的实验，我们制作了TES设备具有不同的电流返回的几何形状。电流返回几何结构反映器件内电流的器件具有更尖锐的过渡，从而允许直接测试电流模型。从这些设备的测量结果表明，电流蜿蜒通过TES低的电阻转变，但流过正常金属功能的40%的正常状态电阻。器件设计之间的过渡锐度的比较表明，自感磁场在确定超导过渡的宽度中起着重要的作用。
Present models of the superconducting-to-normal transition in transition-edge sensors (TESs) do not describe the current distribution within a biased TES. This distribution is complicated by normal-metal features that are integral to TES design. We present a model with one free parameter that describes the evolution of the current distribution with bias. To probe the current distribution experimentally, we fabricated TES devices with different current return geometries. Devices where the current return geometry mirrors current flow within the device have sharper transitions, thus allowing for a direct test of the current-flow model. Measurements from these devices show that current meanders through a TES low in the resistive transition but flows across the normal-metal features by 40% of the normal-state resistance. Comparison of transition sharpness between device designs reveals that self-induced magnetic fields play an important role in determining the width of the superconducting transition.