Optical holonomic single quantum gates with a geometric spin under a zero field

TL;DR

This paper demonstrates the implementation of universal optical holonomic quantum gates on a geometric spin in a nitrogen vacancy center in diamond, enabling fast, fault-tolerant quantum operations under zero magnetic field.

Contribution

It introduces a novel scheme for non-adiabatic holonomic quantum gates using a geometric spin in a degenerate subspace under zero field, controlled by light polarization and detuning.

Findings

Achieved a complete set of Pauli quantum gates.

Demonstrated geometric spin manipulation with high fidelity.

Enabled universal quantum gates with a single optical operation.

Abstract

Realization of fast fault-tolerant quantum gates on a single spin is the core requirement for solid-state quantum-information processing. As polarized light shows geometric interference, spin coherence is also geometrically controlled with light via the spin-orbit interaction. Here, we show that a geometric spin in a degenerate subspace of a spin-1 electronic system under a zero field in a nitrogen vacancy center in diamond allows implementation of optical non-adiabatic holonomic quantum gates. The geometric spin under quasi-resonant light exposure undergoes a cyclic evolution in the spin-orbit space, and acquires a geometric phase or holonomy that results in rotations about an arbitrary axis by any angle defined by the light polarization and detuning. This enables universal holonomic quantum gates with a single operation. We demonstrate a complete set of Pauli quantum gates using the geometric spin preparation and readout techniques. The new scheme opens a path to holonomic quantum computers and repeaters.