Complex Dynamics of Resistively and Inductively Shunted Josephson Junctions
نویسندگان
چکیده
We have measured Nb−AlOx −Nb Josephson tunnel junctions which have resistive shunts with different parasitic inductances. Numerical simulations reveal that specific features in the experimental current-voltage characteristics of these devices are DC signatures of complex AC behavior. Depending on the inductance of the shunt loop and the capacitance of the junction, these features may either appear or disappear as the temperature of the device is increased. Examination of the simulated voltage waveforms allows us to map regions of the parameter space which exhibit complicated behavior. These regions should be avoided when a nearly sinusoidal voltage waveform is desired, as is the case for Josephson junction-based oscillators. The agreement of the experimental and simulated I-V curves also enables us to accurately determine the inductance of the shunts and the capacitance of the junctions. PACS numbers: 85.25.Cp, 75.40.Mg, 85.40.Jq, 74.40.+k Typeset using REVTEX
منابع مشابه
The Superconductor-to-Insulator Transition in Resistively-Shunted Josephson-Junction Arrays
This essay describes the, analytical theory, experimental observations and potential applications of superconductor‐to‐insulator quantum phase transitions in arrays of resistively‐shunted Josephson junctions and superconducting islands dissipatively‐coupled to an external source of single‐particle excitations.
متن کاملJosephson junctions and DC SQUIDS based on Nb/Al technology.
A process for fabricating high-quality Josephson junctions and DC SQUIDs on basis of Nb/Al technology has been developed. DC magnetron sputtering is used for the deposition of the metal layers and the barrier is formed by thermal oxidation of the Al-layer. The junction area of 5 microns x 5 microns is obtained using anodisation. Three types of Josephson tunnel junctions have been prepared: stan...
متن کاملResistively shunted Josephson junctions: QFT predictions versus MC results
During the last fourteen years several exact results were obtained for the so-called boundary sine-Gordon model. In the case of a conformal bulk this 2D boundary quantum field theory describes the universal scaling behavior of the CaldeiraLeggett model of resistively shunted Josephson junctions. In this work, we use a recently developed Monte Carlo technique to test some of the analytical predi...
متن کاملDelayed pulses from high-transparency Josephson junctions
Calculations of the shape and the timing of single-magnetic-flux quanta ~SFQs! generated by high-current-density ‘‘self-shunted’’ Josephson junctions are presented. The junction current is assumed to be due in part to multiple Andreev reflections within the high-transparency barrier. The SFQ pulses from these junctions show several differences when compared to those from lower-current-density r...
متن کاملShapiro steps in Josephson Junctions
We use Ginzburg-Landau theory to describe the phase transition to the superconducting state and the current through a superconductor. Applying quantum mechanics to the Josephson junction following Feynmann’s method the Josephson relations for AC and DC current through the junctions is obtained. The resistively shunted Josephson junction and the resistively and capacitively shunted Josephson jun...
متن کامل