arXiv subjects

Jeffrey V. Cady

Publications and source records attributed to Jeffrey V. Cady.

3 recordsLinked to original sources

arXiv2025

A spin-embedded diamond optomechanical resonator with mechanical quality factor exceeding one million

Diamond optomechanical crystal (OMC) devices with embedded color center spins are promising platforms for a broad range of applications in quantum sensing, networking, and computing applications, offering an interface between a GHz-frequency mechanical mode and both optical photons and coherent spins. A crucial but elusive step towards realizing this platform is to engineer a device with a high-quality factor mechanical mode while preserving the bulk-like coherence of embedded spins. Here we demonstrate sideband-resolved diamond OMCs with mechanical quality factors in excess of $10^6$ at cryogenic temperatures, and find coherence times up to $T_2$ = 270 $μ$s for embedded nitrogen vacancy (NV) centers. Furthermore, we measure these devices across five orders of magnitude in intracavity optical power, demonstrating robust power handling and a high optomechanical cooperativity ($C\gg1$) at cryogenic temperatures that is essential for a broad range of quantum protocols requiring strong, coherent interactions between photons and phonons. These results are enabled by a robust, high-throughput method for forming single-crystal diamond membranes in combination with chemical vapor deposition (CVD) diamond overgrowth with nitrogen $δ$-doping. We discuss the prospects of this platform for hybrid spin-mechanical devices in the quantum regime.

quant-ph↗

arXiv2023

Single-Spin Readout and Quantum Sensing using Optomechanically Induced Transparency

Solid-state spin defects are promising quantum sensors for a large variety of sensing targets. Some of these defects couple appreciably to strain in the host material. We propose to use this strain coupling for mechanically-mediated dispersive single-shot spin readout by an optomechanically-induced transparency measurement. Surprisingly, the estimated measurement times for negatively-charged silicon-vacancy defects in diamond are an order of magnitude shorter than those for single-shot optical fluorescence readout. Our scheme can also be used for general parameter-estimation metrology and offers a higher sensitivity than conventional schemes using continuous position detection.

quant-ph↗

arXiv2016

Topical Review: Spins and mechanics in diamond

There has been rapidly growing interest in hybrid quantum devices involving a solid-state spin and a macroscopic mechanical oscillator. Such hybrid devices create exciting opportunities to mediate interactions between disparate qubits and to explore the quantum regime of macroscopic mechanical objects. In particular, a system consisting of the nitrogen-vacancy defect center in diamond coupled to a high quality factor mechanical oscillator is an appealing candidate for such a hybrid quantum device, as it utilizes the highly coherent and versatile spin properties of the defect center. In this paper, we will review recent experimental progress on diamond-based hybrid quantum devices in which the spin and orbital dynamics of single defects are driven by the motion of a mechanical oscillator. In addition, we discuss prospective applications for this device, including long range, phonon-mediated spin-spin interactions, and phonon cooling in the quantum regime. We conclude the review by evaluating the experimental limitations of current devices and identifying alternative device architectures that may reach the strong coupling regime.

quant-ph↗