1D Josephson chains isolated from the environment by superinductors

Superinductors offer new types of functionality, including non-dissipative high-impedance isolation of quantum circuits from the environment [i]. In our work we studied the chains of Josephson junctions (JJs) and individual JJs isolated from the environment by the superinductors made of strongly disordered Aluminum [ii]. The superinductors have been fabricated as nanowire meanders with small in-plane dimensions (to reduce parasitics) and the kinetic inductance up to 3 µH. We measured the current-voltage characteristics of JJ circuits with the normal-state resistance of individual JJs varied between 1 kΩ and 100 kΩ, and we observed the transition between thermally activated phase diffusion and macroscopic quantum tunneling regimes. We will also discuss application of superinductors for the observation of Bloch oscillations in Josephson circuits.

i. M.T. Bell, I.A. Sadovskyy, L.B. Ioffe, A.Yu. Kitaev, and M.E. Gershenson. Quantum superinductor with tunable non-linearity. Phys. Rev. Lett. 109, 137003 1-5 (2012)
ii. W. Zhang, K. Kalashnikov, W.-S. Lu, P. Kamenov, T. DiNapoli, M.E. Gershenson. Microresonators fabricated from high-kinetic-inductance Aluminum films. arXiv:1807.00210 (2018)