COTUNNELING TRANSPORT AND QUANTUM PHASE TRANSITIONS IN COUPLED JOSEPHSON-JUNCTION CHAINS WITH CHARGE FRUSTRATION
COTUNNELING TRANSPORT AND QUANTUM PHASE TRANSITIONS IN COUPLED JOSEPHSON-JUNCTION CHAINS WITH CHARGE FRUSTRATION
复制标题
具有电荷受阻的耦合约瑟夫森结链中的共隧道传输和量子相变
DOI：
10.1103/physrevlett.81.4240
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发表时间：
1998
影响因子：
8.6
通讯作者：
Sung
中科院分区：
文献类型：
--
作者：
Mahn‐Soo Choi;M. Choi;Taeseung Choi;Sung
本文研究了两个电容耦合超小约瑟夫森结链中的量子相变，重点研究了外电荷效应。系统的粒子-空穴对称性被施加到每个超导岛上的栅极电压打破，并且由此产生的感应电荷向系统引入挫折。在最大阻挫线附近，系统被转化为自旋1/2海森堡反铁磁链，粒子沿着两条链的共同隧穿在输运中发挥着重要作用，并随着约瑟夫森耦合能量的增加，驱动量子相变离开电荷密度波绝缘体。我们还简要地指出，稍微偏离对称线，跃迁的普适类仍然与对称线上的普适类相同，仍然由粒子-空穴对驱动。
We investigate the quantum phase transitions in two capacitively coupled chains of ultra-small Josephson-junctions, with emphasis on the external charge effects. The particle-hole symmetry of the system is broken by the gate voltage applied to each superconducting island, and the resulting induced charge introduces frustration to the system. Near the maximal-frustration line, where the system is transformed into a spin-1/2 Heisenberg antiferromagnetic chain, cotunneling of the particles along the two chains is shown to play a major role in the transport and to drive a quantum phase transition out of the charge-density wave insulator, as the Josephson-coupling energy is increased. We also argue briefly that slightly off the symmetry line, the universality class of the transition remains the same as that right on the line, still being driven by the particle-hole pairs.