Savel'ev Sergey, Rakhmanov A L, Nori Franco
Frontier Research System, The Institute of Physical and Chemical Research (RIKEN), Wako-shi, Saitama, 351-0198, Japan.
Phys Rev Lett. 2007 Feb 16;98(7):077002. doi: 10.1103/PhysRevLett.98.077002. Epub 2007 Feb 14.
We derive a quantum field theory of Josephson plasma waves (JPWs) in layered superconductors, which describes two types of interacting JPW bosonic quanta (one heavy and one lighter). We propose a mechanism of enhancement of macroscopic quantum tunneling (MQT) in stacks of intrinsic Josephson junctions. Because of the long-range interaction between junctions in layered superconductors, the calculated MQT escape rate Gamma has a nonlinear dependence on the number of junctions in the stack. We show that the crossover temperature between quantum and thermal escape increases when increasing the number of junctions. This allows us to quantitatively describe striking recent experiments in Bi2Sr2CaCu2O8+delta stacks.
我们推导了层状超导体中约瑟夫森等离子体波（JPW）的量子场论，该理论描述了两种相互作用的JPW玻色子量子（一种较重，一种较轻）。我们提出了一种增强本征约瑟夫森结堆栈中宏观量子隧穿（MQT）的机制。由于层状超导体中结之间的长程相互作用，计算出的MQT逃逸率Gamma对堆栈中结的数量具有非线性依赖性。我们表明，随着结数量的增加，量子逃逸和热逃逸之间的交叉温度会升高。这使我们能够定量描述最近在Bi2Sr2CaCu2O8+δ堆栈中进行的引人注目的实验。
