Quantum register based on structured diamond waveguide with NV centers

TL;DR

This paper proposes a quantum information processing scheme using NV-centers in diamond nanostructures, enabling fast entanglement and quantum operations via a waveguide mode controlled electrostatically.

Contribution

It introduces a novel cavity-based scheme for NV-center entanglement and quantum gates that are faster than previous laser-assisted methods.

Findings

Controlled-Z operation is an order of magnitude faster.

Numerical modeling optimizes microdisk array geometry.

Spectral characteristics support effective quantum operation implementation.

Abstract

We propose a scheme of quantum information processing with NV-centers embedded inside diamond nanostructure. Single NV-center placed in the cavity plays role of an electron spin qubit which evolution is controlled by microwave pulses. Besides, it couples to the cavity field via optical photon exchange. In their turn, neighbor cavities are coupled to each other through the photon hopping to form a bus waveguide mode. This waveguide mode overlaps with all NV-centers. Entanglement between distant centers is organized by appropriate tuning of their optical frequency relative to the waveguide frequency via electrostatic control without lasers. We describe the controlled-Z operation that is by one order of magnitude faster than in off-resonant laser-assisted schemes proposed earlier. Spectral characteristics of the one-dimensional chain of microdisks are calculated by means of numerical modeling, using the approach analogous to the tight-binding approximation in the solid-state physics. The data obtained allow to optimize the geometry of the microdisk array for the effective implementation of quantum operations.