2D SQIF arrays using 20 000 YBCO highR_nJosephson junctions

Abstract

Superconducting quantum interference filters (SQIFs) have been created using two dimensional arrays of YBCO step-edge Josephson junctions connected together in series and parallel configurations via superconducting loops with a range of loop areas and loop inductances. A SQIF response, as evidenced by a single large anti-peak at zero applied flux, is reported at 77 K for step-edge junction arrays with the junction number N = 1 000 up to 20 000. The SQIF sensitivity (slope of peak) increased linearly with N up to a maximum of 1530 V T−1. Array parameters related to geometry and average junction characteristics are investigated in order to understand and improve the SQIF performance in high temperature superconducting arrays. Initial investigations also focus on the effect of the SQUID inductance factor on the SQIF sensitivity by varying both the mean critical current and the mean inductance of the loops in the array. The RF response to a 30 MHz signal is demonstrated.

High-Tc superconducting quantum interference filters (SQIFs) made by ion irradiation

“…By construction they all lie on the same line, which put stringent constraint on the circuit design. If 1D arrays can be easily realized, it is more challenging to achieve a high performance 2D HTSc SQIF along a geometrically one-dimensional grain boundary [15,16].…”

Magnetic field tunable vortex diode made of YBa2Cu3O7−δ Josephson junction asymmetrical arrays

“…3). Such B-tunability can find application in electronic devices based on multiple JJs such as rapid single flux quantum (RSFQ), 40 SQUIDs, 41 or superconducting quantum interference filters (SQIFs) 42,43 when a tunable preferential direction of flux flow is required. In order to qualitatively understand why efficiency changes sign when B is varied, it is important to understand that usually, during the device's operation, there are many U 0 per array loop involved in the ratchet's dynamics.…”

From single SQUID to superconducting quantum arrays

“…One should note also that the expected progress in Josephson junction fabrication technology, e.g., with a further increase in critical current density of the niobium process or with advancement in high-temperature superconductor technology [37][38][39], will allow improving characteristics of the quantum cells and hence the SQA-based devices.…”