Quantum effects of resistance-shunted Josephson junctions

Takeo Kato*, Masatoshi Imada

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


Thermodynamics and transport properties of resistance-shunted Josephson junctions are studied theoretically in the tight-binding limit EC/EJ ≪ 1, where EC and EJ are a charging energy and a Josephson coupling energy respectively. Based on a phenomenological harmonic-oscillator model, weak coupling region K = RQ/R ≪ 1 is analytically studied, where R and RQ = h/(2e)2 are a shunt resistance and the quantum resistance. In addition to an effective bandwidth 2ℏΔeff, we find that this multi-level system genuinely has a novel crossover at lower energy KℏΔeff below which the density of states becomes strongly degenerate. These two energy scales control the linear DC responses, optical responses, and nonlinear I-V characteristics. The lower energy crossover indicates the existence of a new class of strongly-correlated phenomena beyond the framework of the Kondo problem.

Original languageEnglish
Pages (from-to)203-212
Number of pages10
Journaljournal of the physical society of japan
Issue number1
Publication statusPublished - 2000 Jan
Externally publishedYes


  • Coulomb blockade
  • Dissipation
  • Josephson junctions
  • Macroscopic quantum effects
  • Superconductor-insulator transition

ASJC Scopus subject areas

  • General Physics and Astronomy


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