Vanishing quasiparticle density in a hybrid Al/Cu/Al single-electron transistor
Vanishing quasiparticle density in a hybrid Al/Cu/Al single-electron transistor
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DOI：
10.1103/physrevb.85.012504
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发表时间：
2012-01-20
影响因子：
3.7
通讯作者：
Pekola, J. P.
中科院分区：
文献类型：
--
作者：
Saira, O-P;Kemppinen, A.;Pekola, J. P.
许多基于超导铝的纳米电子器件可实现的保真度受到残余非平衡准粒子密度 n(qp) 或间隙中准粒子态密度（以达因参数伽马为特征）的限制。我们从 Al/Cu/Al 单电子晶体管上进行的输运测量推断出上限 n(qp) < 0.033 mu m(-3) 和 gamma < 1.6 x 10(-7)，将之前的结果提高了一个数量级。由于有效的微波屏蔽和准粒子弛豫，超导引线中的准粒子的典型数量为零。
The achievable fidelity of many nanoelectronic devices based on superconducting aluminum is limited by either the density of residual nonequilibrium quasiparticles n(qp) or the density of quasiparticle states in the gap, characterized by Dynes parameter gamma. We infer upper bounds n(qp) < 0.033 mu m(-3) and gamma < 1.6 x 10(-7) from transport measurements performed on Al/Cu/Al single-electron transistors, improving previous results by an order of magnitude. Owing to efficient microwave shielding and quasiparticle relaxation, a typical number of quasiparticles in the superconducting leads is zero.