Design of an On-Chip Superconducting Microwave Circulator with Octave Bandwidth

Abstract

We present a design for a superconducting, on-chip circulator composed of dynamically modulated transfer switches and delays. Design goals are set for the multiplexed readout of superconducting qubits. Simulations of the device show that it allows for low-loss circulation (insertion loss < 0.35 dB and isolation > 20 dB) over an instantaneous bandwidth of 2.3 GHz. As the device is estimated to be linear for input powers up to −65 dBm, this design improves on the bandwidth and powerhandling of previous superconducting circulators [1][2][3] by over a factor of 50, making it ideal for integration with broadband quantum limited amplifiers [4][5][6].

Charge-Noise Insensitive Chiral Photonic Interface for Waveguide Circuit QED

“…The lateral dimension of the entire circulator can be a few millimeters [39]. These properties make our chiral interface highly attractive for, e.g., on-chip routing of microwave signals [10,[14][15][16][17][18][19][20][21][22][23]36,37] as well as fundamental studies of chiral waveguide QED [3,4,7,46].…”

“…However, such components are off-chip, requiring additional space inside the experimental apparatus. Most of the existing proposals for on-chip circulators break TRS by tailored active control [10,[14][15][16][17][18][19][20][21][22][23], e.g., via a synthetic magnetic field [22], or by dynamically modulating switches and delays [23]. On-chip circulators that can be operated in a passive form, thereby simplifying its experimental implementations, however remain elusive.…”

Solid-State Qubits: 3D Integration and Packaging

“…Several alternative approaches are currently under consideration, including commercial multi-coax assemblies and superconducting flex-print [42,43] and rigid-flex wiring [44]. There are also efforts underway to develop on-chip microwave isolators to replace existing bulky components made with magnetic materials [45,46].…”

Broadband Tunable Phase Shifter For Microwaves

“…Here, superconducting circuits with Josephson junctions exhibit a solid and scalable technology platform stemming from their mature lithographic fabrication processes [2]. During the recent decades, fascinating superconducting rf components for the toolbox have been demonstrated, such as Josephson parametric amplifiers [3,4], kinetic inductance travelling-wave amplifiers [5,6], switches [7,8], circulators [9,10], isolators [11], beam splitters [12,13], phase shifters [14,15], and photon detectors [16][17][18]. In the future, these may be integrated into monolithic circuits for sophisticated quantum signal processing.…”