Tunable and Transferable Diamond Membranes for Integrated Quantum Technologies.

Guo, Xinghan; Delegan, Nazar; Karsch, Jonathan C; Li, Zixi; Liu, Tianle; Shreiner, Robert; Butcher, Amy; Awschalom, David D et al. · Nano Lett · 2021

basic_science · Level V

Where this comes from

Abstract

Color centers in diamond are widely explored as qubits in quantum technologies. However, challenges remain in the effective and efficient integration of these diamond-hosted qubits in device heterostructures. Here, nanoscale-thick uniform diamond membranes are synthesized via "smart-cut" and isotopically (<sup>12</sup>C) purified overgrowth. These membranes have tunable thicknesses (demonstrated 50 to 250 nm), are deterministically transferable, have bilaterally atomically flat surfaces (<i>R<sub>q</sub></i> ≤ 0.3 nm), and bulk-diamond-like crystallinity. Color centers are synthesized via both implantation and in situ overgrowth incorporation. Within 110-nm-thick membranes, individual germanium-vacancy (GeV<sup>-</sup>) centers exhibit stable photoluminescence at 5.4 K and average optical transition line widths as low as 125 MHz. The room temperature spin coherence of individual nitrogen-vacancy (NV<sup>-</sup>) centers shows Ramsey spin dephasing times (<i>T</i><sub>2</sub><sup>*</sup>) and Hahn echo times (<i>T</i><sub>2</sub>) as long as 150 and 400 μs, respectively. This platform enables the straightforward integration of diamond membranes that host coherent color centers into quantum technologies.

Medical subject headings