Extended T2 times of shallow implanted NV in chemically mechanically polished diamond

TL;DR

This study demonstrates that chemical mechanical polishing (CMP) significantly enhances the spin lifetime (T2) of shallow implanted NV centers in diamond, achieving up to 355 microseconds, which is promising for scalable quantum applications.

Contribution

The paper introduces a CMP process that improves the T2 spin lifetime of shallow NV centers in diamond compared to traditional etching methods.

Findings

CMP yields longer T2 times than ICP-RIE.

Median T2 of 355 microseconds achieved with CMP.

CMP is scalable for industrial diamond processing.

Abstract

Mechanical polishing of diamond is known to be detrimental to the spin lifetime and strain environment of near-surface defects. By utilising a chemical mechanical polishing (CMP) process, we demonstrate that we can achieve 13C-limited spin lifetimes of shallow implanted (<34 nm) NV centres in an industrially scalable process. We compare spin lifetimes (T2) of three diamonds processed with CMP with one processed by inductively-coupled plasma reactive ion etching (ICP-RIE), and observe an increased median T2 of 355 microseconds in the CMP-processed samples for 15NV centres implanted and annealed under identical conditions.