A two-stage dc SQUID is strongly coupled to an electrical resonator at 1.6 kHz with quality factor Q=1.1 × 106 in order to simulate the behaviour of the SQUID on a resonant gravitational wave detector. A capacitive damping network is successfully employed in order to avoid the instabilities due to the real part of the SQUID dynamic input impedance. The coupled energy resolution is 300 ℏ at 4.2 K, scales with temperature, and is not significantly worsened by the coupling to the resonator and by the damping network. © 2001 Elsevier Science B.V. All rights reserved.
Vinante, A., Bonaldi, M., Falferi, P., Cerdonio, M., Mezzena, R., Prodi, G. A., & Vitale, S. (2002). Stabilization and optimization of a two-stage dc SQUID coupled to a high Q resonator. In Physica C: Superconductivity and its Applications (Vol. 368, pp. 176–180). https://doi.org/10.1016/S0921-4534(01)01162-5