Southwest Quantum Information and Technology

Donor qubits in ZnO

Presenting Author: Vasileios Niaouris, University of Washington
Contributing Author(s): Xiayu Linpeng, Maria L.K. Viitaniemi, Aswin Vishnuradhan, Y. Kozuka, Cameron Johnson, M. Kawasaki, Kai-Mei C. Fu

A new spin qubit system for quantum network applications is an electron bound to a neutral donor (D0) in the direct bandgap semiconductor ZnO. In this system we seek to combine promising spin properties with strong radiative efficiency to an excited state. In the past two years, our group has demonstrated optical initialization and has measured the spin properties of Ga donor ensembles in ZnO: T1 = 140ms (X T) at B=2.25T and T=1.5K & T2 = 50+-13μs (Y T) at B=5T and T=5.5K [ref: Xiayu Linpeng et al., Coherence Properties of Shallow Donor Qubits in ZnO, Phys. Rev. Applied 10, 064061 (2018)]). We have also observed a B^-4 dependence on T1 which is inconsistent with our current understanding of spin-orbit coupling in the material. In this work we show that we are able to extend T1 to more than 800 ms and report on progress toward (1) understanding the longitudinal spin-relaxation mechanism and (2) integrating microwave control of the qubit ensembles.

(Session : from 5:00pm - 7:00pm)