2016/07/13 by V. Pierro, Vincenzo Pierro, Г. Филатрелла +1
Computer Science · Physics and Astronomy · #Biasing #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Context (archaeology) #Josephson effect #Mesoscopic physics #Open quantum system #Physics #Quantum #Quantum Information and Cryptography #Quantum Zeno effect #Quantum and electron transport phenomena #Quantum mechanics #Voltage #cond-mat.supr-con #physics.ins-det #quant-ph
paper · pdf · doi:10.1103/physreva.94.042116
published as Phys. Rev. A 94, 042116 (2016) · 9 pages, 9 figures
arxiv created 2016/07/13 · openalex created_date 2016/07/22 · openalex publication_date 2016/10/19 · arxiv updated 2016/10/24 · openalex updated_date 2026/08/05
The quantum character of Josephson junctions is ordinarily revealed through the analysis of the switching currents, i.e., the current at which a finite voltage appears: A sharp rise of the voltage signals the passage (tunnel) from a trapped state (the zero voltage solution) to a running state (the finite voltage solution). In this context, we investigate the probability distribution of the Josephson-junction switching current taking into account the effect of the bias sweeping rate and introducing a simple nonideal quantum measurement scheme. The measurements are modeled as repeated voltage samplings at discrete time intervals, that is, with repeated projections of the time-dependent quantum solutions on the static or the running states, to retrieve the probability distribution of the switching currents. The distribution appears to be immune to the quantum Zeno effect, and it is close to, but distinguishable from, the Wentzel-Kramers-Brillouin approximation. For energy barriers comparable to the quantum fundamental energy state and in the fast bias current ramp rate the difference is neat, and remains sizable in the asymptotic slow rate limit. This behavior is a consequence of the quantum character of the system that confirms the presence of a backreaction of quantum measurements on the outcome of mesoscopic Josephson junctions.