Minute-long quantum coherence enabled by electrical depletion of magnetic noise

TL;DR

This paper demonstrates that electrical depletion in silicon carbide diodes can significantly reduce magnetic noise, leading to record-long coherence times for electron and nuclear spins, advancing solid-state quantum technologies.

Contribution

It introduces a method to enhance quantum coherence in SiC spin qubits via bias-controlled depletion of magnetic noise sources, integrating quantum and electronic device functionalities.

Findings

Record electron spin coherence times achieved.

Nuclear spin Hahn-echo times extended to minutes.

Magnetic noise suppression through electrical depletion.

Abstract

Integrating solid-state spin defects into classical electronic devices can enable new opportunities for quantum information processing that benefit from existing semiconductor technology. We show, through bias control of an isotopically purified silicon carbide (SiC) p-i-n diode, the depletion of not only electrical noise sources but also magnetic noise sources, resulting in record coherences for SiC electron spin qubits. We also uncover complementary improvements to the relaxation times of nuclear spin registers controllable by the defect, and measure diode-enhanced coherences. These improvements lead to record-long nuclear spin Hahn-echo times on the scale of minutes. These results demonstrate the power of materials control and electronic device integration to create highly coherent solid-state quantum network nodes and processors.