Search Menu
Photonics Media Photonics Marketplace Photonics Spectra BioPhotonics Vision Spectra Photonics Showcase Photonics ProdSpec Photonics Handbook

Defect Control Yields More Reliable Qubits

Facebook Twitter LinkedIn Email
CAMBRIDGE, Mass., Dec. 30, 2014 — Enhancing the fluorescent light emission from atomic defects in diamond could be a key step toward creating reliable qubits for quantum computers.

A team of researchers from several institutions has demonstrated photonic cavities with Q factors of up to 24,000 by carefully controlling the nitrogen vacancy (NV) centers within.

NV centers contain an unpaired electron that can store information in its spin. That information can be read by observing the intensity of particular frequencies of the light that the NV center emits when illuminated by a laser.

A diamond photonic cavity with nanoscale holes containing NV centers.
A scanning electron microscope image of a diamond photonic cavity shows nanoscale holes etched through the layer containing NV centers. The scale bar indicates 200 nm. Courtesy of Evelyn Hu/Harvard University.

At room temperatures, this emission includes multiple sideband frequencies, making it difficult to interpret. The photonic cavity, which consists of a pattern of nanoscale holes, amplifies the most important element of the signal.

“A photonic cavity that is properly matched to the NVs can substantially augment their capabilities,” said Harvard University professor Dr. Evelyn Hu. “Strong spatial overlap is the hardest (task) to achieve in designing and fabricating a photonic cavity for NV centers.”

The team used delta doping to control the vertical position of the atomic defects, enhancing the intensity of photonic cavity emissions by roughly a factor of 30.

The technique confines NV centers to a layer approximately 6 nm thick, sandwiched inside a diamond membrane approximately 200 nm thick. The researchers then etched holes into the membrane to create the photonic cavities.

Further enhancement could come from also controlling the horizontal position of the defects. The team is now working on ways to achieve full 3-D control.

The work was published in Applied Physics Letters (doi: 10.1063/1.4904909).

For more information, visit
Dec 2014
Research & TechnologyAmericasMassachusettsHarvardEvelyn Huquantum computingphotonic cavityqubit

back to top
Facebook Twitter Instagram LinkedIn YouTube RSS
©2023 Photonics Media, 100 West St., Pittsfield, MA, 01201 USA, [email protected]

Photonics Media, Laurin Publishing
x We deliver – right to your inbox. Subscribe FREE to our newsletters.
We use cookies to improve user experience and analyze our website traffic as stated in our Privacy Policy. By using this website, you agree to the use of cookies unless you have disabled them.