The novel device produces a ‘nanojet’ of light and holds promise to advance scalable quantum technologies.
Researchers at the Institute for Quantum Computing (IQC) at the University of Waterloo have demonstrated a nanoscale optical device that makes it easier to probe quantum systems with light to enable more efficient quantum sensors and solid-state quantum computing systems. The new device was demonstrated in diamond as a proof of principle.
This optical device has the potential to make quantum sensors better at detecting weak magnetic fields, which could enhance technologies in biomedical imaging or navigation in GPS-denied environments. It could also advance solid-state quantum computing architectures by improving control and readout of individual quantum bits (qubits), and the transfer of quantum information between them.
Our new approach offers a powerful and practical route to enhance light–matter interaction in solid-state platforms."
Solid-state quantum platforms such as diamond, silicon carbide, and silicon can host atom-like defects, also known as quantum emitters or color centers, that can serve as qubits. These defects can be initialized, controlled, and read out with laser light, and in many cases can also act as solid-state single-photon sources.
In practice, however, aiming a laser at a single defect can be difficult. Additionally, efficiently collecting the optical signal is challenging because these materials have a high refractive index, causing much of the light emitted by the defects to remain trapped inside the material rather than being collected.
That’s the problem Bajcsy’s group aims to solve with a novel device reported in a new paper Probing Individual Quantum Emitters in Bulk Semiconductors via Photonic Nanojets published in Science Advances.
Dr. Michal Bajcsy's group designed a quantum device in diamond that funnels and aims a highly localized beam of photons at single engineered defects in diamond and is optimized to extract photons. Better collecting and controlling light has applications in quantum sensing and solid-state quantum computing architecture.
The research was supported in part by the Canada First Research Excellence Fund through the Transformative Quantum Technologies (TQT) program at IQC.