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05:39
Scalable Quantum Integrated Circuits on Superconducting Two-Dimensional Electron Gas Platform
Published on: August 2, 2019
Quantum terahertz electrodynamics and macroscopic quantum tunneling in layered superconductors
Sergey Savel'ev1, A L Rakhmanov, Franco Nori
1Frontier Research System, The Institute of Physical and Chemical Research (RIKEN), Wako-shi, Saitama, 351-0198, Japan.
Physical Review Letters
|March 16, 2007
Summary
We developed a quantum theory for Josephson plasma waves (JPWs) in layered superconductors. This theory explains enhanced macroscopic quantum tunneling (MQT) in Josephson junction stacks, showing a nonlinear dependence on the number of junctions.
Area of Science:
- Condensed Matter Physics
- Quantum Field Theory
- Superconductivity
Background:
- Layered superconductors exhibit complex quantum phenomena.
- Intrinsic Josephson junctions are crucial for studying quantum effects in these materials.
Purpose of the Study:
- To derive a quantum field theory for Josephson plasma waves (JPWs).
- To propose and analyze a mechanism for enhancing macroscopic quantum tunneling (MQT) in stacks of intrinsic Josephson junctions.
Main Methods:
- Derivation of a quantum field theory for interacting JPW bosonic quanta.
- Calculation of the MQT escape rate (Gamma) considering long-range junction interactions.
- Analysis of the temperature dependence of quantum and thermal escape crossover.
Main Results:
- The theory describes two types of interacting JPW bosonic quanta (heavy and light).
- The MQT escape rate exhibits a nonlinear dependence on the number of junctions in a stack.
- The crossover temperature between quantum and thermal escape increases with the number of junctions.
Conclusions:
- The developed quantum field theory quantitatively describes recent experiments in Bi2Sr2CaCu2O8+delta stacks.
- The findings offer insights into quantum tunneling enhancement in layered superconductors.
- The study highlights the role of long-range interactions in MQT phenomena.
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