Ultra long spin coherence time for Fe³⁺ in ZnO: A new spin qubit

Hahn-Meitner-Institut Berlin, Abt. Silizium-Photovoltaik - Kekuléstr. 5, 12489 Berlin, Germany, EU

Corresponding author: jerome.tribollet@aliceadsl.fr

Received: 1 August 2008
Accepted: 8 September 2008

Abstract

We show by means of two pulse electron spin echo experiments on Fe³⁺ transition metal ions in natural ZnO that their spins S = have a spin coherence time limited at T = 6 K first by instantaneous diffusion (≈ 150 μs), then by nuclear spectral diffusion (≈ 450 μs) and ultimately by spin-lattice processes (≈ 1.4 ms). We predict a spin coherence time in the millisecond range for such a spin qubit in isotopically and chemically purified ZnO. The spin state of a single Fe³⁺ spin qubit could be readout by optical methods and it could be coherently manipulated using pulsed electron spin resonance (ESR) methods. A free carrier electrically gated between two nearby Fe³⁺ ions could efficiently couple two Fe³⁺ spin qubits. All those elements suggest the high potential of the Fe³⁺ spin qubits in ZnO for the implementation of a scalable ESR quantum computer.