2023/12/22 by Carles Altimiras, Altimiras, Carles, D. Estève +7
Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Physics of Superconductivity and Magnetism #Quantum Physics (quant-ph) #Quantum and electron transport phenomena #Superconductivity (cond-mat.supr-con)
paper · pdf · doi:10.48550/arxiv.2312.14754
openalex publication_date 2023/12/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We investigate the resistively shunted Josephson junction (RSJ) at equilibrium, using linear response, an exact path integral technique and symmetry considerations. All three approaches independently lead to conclude that the superconducting - insulating quantum phase transition long believed to occur in the RSJ, cannot exist. For all parameters, we find that shunting a junction makes it more superconducting. We reveal that the UV cutoff of the resistor plays an unforeseen key role in these systems, and show that the erroneous prediction of an insulating state resulted in part from assuming it would not. We also explain why the RSJ physics differs from that of 1D quantum impurity problems. Our results fully support and confirm the experimental invalidation of this quantum phase transition by Murani et al. in 2020.