Dissipative charge transport in diffusive superconducting double-barrier junctions
Dissipative charge transport in diffusive superconducting double-barrier junctions
复制标题
扩散超导双势垒结中的耗散电荷传输
DOI：
10.1103/physrevb.83.184517
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发表时间：
2011
影响因子：
3.7
通讯作者：
V. Shumeiko
中科院分区：
文献类型：
--
作者：
E. Bezuglyi;E. Bratus';V. Shumeiko
本文解决了相干多次Andreev反射（MAR）问题，计算了Josephson SINIS结的电流-电压特性（IVC），其中S是局域平衡超导库，I是隧道势垒，N是一条长度远小于相干长度的短扩散正常线，其电阻远小于隧道势垒的电阻。这种结中的电荷传输状态定性地取决于在停留时间τ（d）期间累积的电子和回射空穴之间的相对相移的特征值γ = τ（d）Δ。在小的电子-空穴退相γ << 1的限制下，我们的解决方案恢复了扩展到MAR区域的短介观连接器的已知公式。在大的失相时，IVC中的次谐波间隙结构与伽马（-1）成比例，其因此起到有效隧穿参数的作用。在此极限下，偶间隙次谐波被共振增强，并且IVC表现出具有负微分电阻的部分。
We solve the coherent multiple Andreev reflection (MAR) problem and calculate current-voltage characteristics (IVCs) for Josephson SINIS junctions, where S are local-equilibrium superconducting reservoirs, I denotes tunnel barriers, and N is a short diffusive normal wire, the length of which is much smaller than the coherence length, and the resistance is much smaller than the resistance of the tunnel barriers. The charge transport regime in such junctions qualitatively depends on a characteristic value gamma = tau(d)Delta of relative phase shifts between the electrons and retroreflected holes accumulated during the dwell time tau(d). In the limit of small electron-hole dephasing gamma << 1, our solution recovers a known formula for a short mesoscopic connector extended to the MAR regime. At large dephasing, the subharmonic gap structure in the IVC scales with gamma(-1), which thus plays the role of an effective tunneling parameter. In this limit, the even gap subharmonics are resonantly enhanced, and the IVC exhibits portions with negative differential resistance.