Quantum phase transitions in Josephson-junction chains
Quantum phase transitions in Josephson-junction chains
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DOI：
10.1103/physrevb.57.r716
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发表时间：
1998-01-01
影响因子：
3.7
通讯作者：
Lee, SI
中科院分区：
文献类型：
--
作者：
Choi, MS;Yi, J;Lee, SI
本文研究了一维超小超导晶粒链中的量子相变，同时考虑了自电容和结电容。在零温度下，该系统被转换成一个二维系统的经典涡旋，其中的结电容引入各向异性的涡旋之间的相互作用。这导致了Berezinskiii-Kosterlitz-无磁类型的超导体-绝缘体转变，因为约瑟夫森耦合能量与充电能量的比率是变化的。据发现，结电容起着类似的耗散的作用，并倾向于抑制量子波动;然而，绝缘体区域生存，即使对于任意大的值的结电容。
We investigate the quantum phase transition in a one-dimensional chain of ultrasmall superconducting grains, considering both the self-and junction capacitances. At zero temperature, the system is transformed into a two-dimensional system of classical vortices, where the junction capacitance introduces anisotropy in the interaction between vortices. This leads to the superconductor-insulator transition of the Berezinskii-Kosterlitz-Thouless type, as the ratios of the Josephson coupling energy to the charging energies are varied. It is found that the junction capacitance plays a role similar to that of dissipation and tends to suppress quantum fluctuations; nevertheless the insulator region survives even for arbitrarily large values of the junction capacitance.