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

Mechanical polishing of diamond is known to be detrimental to the spin coherence time and strain environment of near-surface defects via intrinsic introduction of subsurface damage: this damage is typically removed by inductively coupled plasma reactive ion etching (ICP-RIE). By utilizing a chemical mechanical polishing (CMP) process to prepare ⟨001⟩ diamond surfaces, we demonstrate that we can achieve 13C-limited spin lifetimes of shallow implanted (≤34 nm) nitrogen vacancy (NV) centers in an industrially scalable process. We compare spin lifetimes (T2) of three diamonds processed with CMP with one processed by ICP-RIE and observe an increased median T2 of 340 μs in the CMP-processed samples for 15NV centers implanted and annealed under identical conditions.