On-chip microwave-spin-plasmon interface (MSPI)

TL;DR

This paper presents an on-chip integrated structure for NV spin-based quantum applications, combining optical readout and microwave control in a single material layer to enable compact quantum sensors and processing devices.

Contribution

The work demonstrates a novel, single-material, one-step patterned on-chip structure for NV center readout and control, reducing device size and fabrication complexity.

Findings

Successful integration of NV centers with on-chip waveguides and microwave control.

Reduced device dimensions and fabrication steps compared to bulk optics approaches.

Potential for development of ultra-compact quantum sensors and processors.

Abstract

On-chip scalable integration represents a major challenge for practical quantum devices. One particular challenge is to implement on-chip optical readout of spins in diamond. This readout requires simultaneous application of optical and microwave fields along with an efficient collection of fluorescence. The readout is typically accomplished via bulk optics and macroscopic microwave transmission structures. We experimentally demonstrate an on-chip integrated structure for nitrogen vacancy (NV) spin-based applications, implemented in a single material layer with one patterning step. A nanodiamond with multiple NV centres is positioned at the end of the groove waveguide milled in a thick gold film. The gold film carries the microwave control signal while the groove waveguide acts as a fluorescence collector, partially filtering out the pump excitation. As a result, the device dimensions and fabrication complexity are substantially reduced. Our approach will foster further development of ultra-compact nanoscale quantum sensors and quantum information processing devices on a monolithic platform. NV centre-based nanoscale sensors are the most promising application of the developed interface.