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Register a new userModelling the transfer function of two-dimensional SQUID and SQIF arrays with thermal noise
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Marc Gali Labarias Dr
Publication date
2021
fields
Physics
and research's language is
English
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We present a theoretical model for 2D SQUID and SQIF arrays with over-damped Josephson junctions for uniform bias current injection at 77 K. Our simulations demonstrate the importance of including Johnson thermal noise and reveal that the mutual inductive coupling between SQUID loops is of minor importance. Our numerical results establish the validity of a simple scaling behaviour between the voltages of 1D and 2D SQUID arrays and show that the same scaling behaviour applies to the maximum transfer functions. The maximum transfer function of a 2D SQUID array can be further optimised by applying the optimal bias current which depends on the SQUID loop self-inductance and the junction critical current. Our investigation further reveals that a scaling behaviour exits between the maximum transfer function of a 2D SQUID array and that of a single dc-SQUID. Finally, we investigate the voltage response of 1D and 2D SQIF arrays and illustrate the effects of adding spreads in the heights and widths of SQUID loops.
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We investigate theoretically the effect of the coupling radius on the transfer function in 1D and 2D SQUID arrays with different number of Josephson junctions in parallel and series at 77 K. Our results show a plateauing of the array maximum transfer function with the number of junctions in parallel. The plateauing defines the array coupling radius which we show increases with decreasing the normalised impedance of the SQUID loop inductance. The coupling radius is found to be independent of the number of junctions in series. Finally, we investigate the voltage versus magnetic field response and maximum transfer function of one 1D and two 2D SQIF arrays with different SQUID loop area distributions.
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