2024/11/10 by Samuel Feldman, Feldman, Samuel, Andrey Rogachev +1
Physics and Astronomy · #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Physics of Superconductivity and Magnetism #Quantum Physics (quant-ph) #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con) #Surface and Thin Film Phenomena
paper · pdf · doi:10.48550/arxiv.2411.06492
openalex publication_date 2024/11/10 · openalex created_date 2024/11/15 · openalex updated_date 2026/07/28
Theoretically, Josephson junction (JJ) arrays can exhibit either a superconducting or insulating state, separated by a quantum phase transition (QPT). In this work, we analyzed published data on QPTs in three one-dimensional arrays and two two-dimensional arrays using a recently developed phenomenological model of QPTs. The model is based on the insight that the scaled experimental data depend in a universal way on two characteristic length scales of the system: the microscopic length scale L0 from which the renormalization group flow starts, and the dephasing length, Lφ(T) as given by the distance travelled by system-specific elementary excitations over the Planckian time. Our analysis reveals that the data for all five arrays (both 1D and 2D) can be quantitatively and self-consistently explained within the framework of interacting superconducting plasmons. In this picture, Lφ=vpℏ/kB T, and L0 ≈ Λ, where vp is the speed of the plasmons and Λ is the Coulomb screening length of the Cooper pairs. We also observe that, in 1D arrays, the transition is significantly shifted towards the insulating side compared to the predictions of the sine-Gordon model. Finally, we discuss similarities and differences with recent microwave studies of extremely long JJ chains, as well as with the pair-breaking QPT observed in superconducting nanowires and films.