Infinite-randomness fixed point of the quantum superconductor-metal transitions in amorphous thin films
Infinite-randomness fixed point of the quantum superconductor-metal transitions in amorphous thin films
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DOI：
10.1103/physrevb.99.054515
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发表时间：
2018-09
影响因子：
3.7
通讯作者：
Nicholas A. Lewellyn;Ilana M. Percher;J. Nelson;J. García‐Barriocanal;I. Volotsenko;A. Frydman;T. Voj
中科院分区：
文献类型：
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作者：
Nicholas A. Lewellyn;Ilana M. Percher;J. Nelson;J. García‐Barriocanal;I. Volotsenko;A. Frydman;T. Voj
无序非晶氧化铟薄膜的磁场调谐量子超导体-绝缘体转变是量子相变研究的一个范例，并表现出幂律标度行为。对于低无序的超导氧化铟薄膜，如本文所报道的，高场态似乎是量子校正的金属。在这些薄膜中的超导体-金属过渡的电阻数据在这里示出服从一个激活的缩放形式适当的量子相变控制的无限随机不动点的普遍性类的随机横向场伊辛模型。崩溃的场依赖性电阻与温度的数据是使用激活的缩放形式适合于这个普适性类，使用通过修改后的形式的幂律缩放分析确定的值。这种奇异的行为表现出超导金属过渡的薄膜是由超导稀有区域浸入金属基体中的耗散动力学引起的，正如最近的重整化群理论所预测的那样。所观察到的等温线的涂抹交叉点是由于校正缩放，这是预期附近的一个无限的随机性临界点，其中的逆无序强度作为一个不相关的缩放变量。
The magnetic-field-tuned quantum superconductor-insulator transitions of disordered amorphous indium oxide films are a paradigm in the study of quantum phase transitions, and exhibit power-law scaling behavior. For superconducting indium oxide films with low disorder, such as the ones reported on here, the high-field state appears to be a quantum-corrected metal. Resistance data across the superconductor-metal transition in these films are shown here to obey an activated scaling form appropriate to a quantum phase transition controlled by an infinite randomness fixed point in the universality class of the random transverse-field Ising model. Collapse of the field-dependent resistance vs. temperature data is obtained using an activated scaling form appropriate to this universality class, using values determined through a modified form of power-law scaling analysis. This exotic behavior of films exhibiting a superconductor-metal transition is caused by the dissipative dynamics of superconducting rare regions immersed in a metallic matrix, as predicted by a recent renormalization group theory. The smeared crossing points of isotherms observed are due to corrections to scaling which are expected near an infinite randomness critical point, where the inverse disorder strength acts as an irrelevant scaling variable.