A three-dimensional multimode lumped-element resonator for collective spin manipulation and dispersive readout

TL;DR

This paper introduces a 3D multimode microwave resonator that enables homogeneous collective spin manipulation and dispersive readout, demonstrating strong coupling with NV centers at millikelvin temperatures.

Contribution

The work presents a novel 3D multimode resonator design with engineered antisymmetric modes for efficient spin ensemble control and readout, advancing hybrid quantum systems.

Findings

Achieved collective strong coupling of 5.0 MHz with NV centers.

Demonstrated non-destructive dispersive readout.

Developed a compact, tunable, high-homogeneity resonator.

Abstract

We report a three-dimensional lumped-element multimode microwave resonator that enables homogeneous collective manipulation and dispersive readout of a macroscopic spin ensemble. By exploiting geometric symmetry, two antisymmetric modes with strongly suppressed cross-talk are engineered to spatially overlap and couple to the same ensemble at distinct frequencies. Using negatively charged nitrogen-vacancy centers in diamond at 28 mK, we observe collective strong coupling with a coupling strength of 5.0 MHz and demonstrate non-destructive dispersive readout via a detuned mode. The compact design, tunable coupling, and high field homogeneity make this resonator a versatile device for hybrid spin-photon systems and multimode solid-state quantum technologies.