Southwest Quantum Information and Technology

Shallow donor spin-qubits in ZnO - Using ion implantation and focused-ion beam milling for donor formation and photonics integration

Presenting Author: Vasileios Niaouris, University of Washington
Contributing Author(s): Christian Zimmermann, Xingyi Wang, Michael Titze, Bethany Matthews, Ethan Hansen, Samuel H. D’Ambrosia, Maria L. K. Viitaniemi, Simon P. Watkins, Steven R. Spurgeon, Edward S. Bielejec, Kai-Mei C. Fu

Neutral shallow donors (D0) in ZnO such as In, Ga, and Al substituting for Zn are promising solid-state spin qubits for quantum technologies. The D0 are optically coupled to donor bound excitons. Studying donor ensembles, we have demonstrated narrow inhomogeneous linewidths (~10GHz), long spin relaxation time (T1, up to 0.48 sec at 1.75 T) [1], spin initialization via optical pumping [2], and all-optical coherent control [3]. In this contribution, we will be discussing the ability to control the number of donors accessed optically via implantation and the potential to use focused ion beam milling (fibbing) to fabricate on ZnO. Through implantation and annealing, we can form In donors within a thin layer of ZnO, with favorable optical and coherent properties. Via fibbing, a slice of different thicknesses, ranging between 0.1 and 3 um, was cut out of the ZnO crystal. Due to the reduced thickness, we can probe smaller ensembles that retain good optical properties (after annealing) and identify candidates for stable single emitters. Combining donor implantation and fibbing, we aim to fabricate photonic structures around implanted donors, a significant step towards scaling this emerging technology. [1] V. Niaouris, et al., Phys. Rev B 105, 195202 (2022) [2] X. Linpeng et al., Phys. Rev. Appl. 10, 064061 (2018) [3] M. L. K. Viitaniemi, et al., Nano Lett. 22, 5 (2022) *Supported by the U.S. DOE (DE-SC0020378), the NSF (1820614), and the Army Research Office MURI Grant (18057522).

(Session 13 : from 3:45 pm - 4:15 pm)