Design and Testing of Bimodal Loop-Gap Resonators for Multi-Spin Quantum Systems

Multi-spin systems are promising building blocks for quantum computers, since interactions between coupled spins can enable communication and information transfer. To study these interactions, our project uses bimodal loop-gap resonators that operate at two distinct frequencies separated by >1 GHz, allowing control of two spin systems at once. We design and test these resonators using both simulations and benchtop measurements to ensure that their resonant frequencies align with the targeted spin transitions. However, the most important test is to measure how well the resonators couple to spin systems at their operating frequencies, which is currently done at cryogenic temperatures, making the process slow and limiting other experiments. To make this process more efficient and to refine resonator designs before cooling, we are developing an integrated room-temperature design and testing pipeline that allows us to study resonator performance and coupling to spin systems directly on the bench. We will present our progress toward this goal and our explorations of systems such as NV-centers in diamond and irradiated quartz as room-temperature spin-echo samples.