Anomalous magnetoresistance near the superconductor-insulator transition in ultrathin films of α-MoxSi1-x
Anomalous magnetoresistance near the superconductor-insulator transition in ultrathin films of α-MoxSi1-x
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DOI：
10.1103/physrevb.58.2816
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发表时间：
1998-08-01
影响因子：
3.7
通讯作者：
Kokubo, N
中科院分区：
文献类型：
--
作者：
Okuma, S;Terashima, T;Kokubo, N
我们对一系列 4 nm 厚的非晶 MoxSi1-x 薄膜在温度 T 降至接近 0.05 K 和场 B 高达 15 T 时的零场和场驱动超导-绝缘体转变进行了系统研究。对于超导薄膜，我们观察到磁阻 R(B) 出现异常峰值，并且在高于临界场的低温下，随着 B 的增加，R(B) 随之减小。 B-xxC。这一结果，加上发现绝缘膜的磁阻始终为正值，可能表明即使在 T-->0 的极限内 B>B-xxC 时也存在局部库珀对。
We have made systematic studies for both the zero-field and field-driven superconductor-insulator transitions in a series of 4-nm-thick films of amorphous MoxSi1-x at temperatures T down to similar to 0.05 K and fields B up to 15 T. For superconducting films, we have observed an anomalous peak in the magnetoresistance R(B) and a subsequent decrease in R(B) with increasing B at low temperatures in fields higher than the critical field B-xxC. This result, together with finding that the magnetoresistance is always positive for insulating films, may suggest the presence of localized Cooper pairs even at B>B-xxC in the limit of T-->0.