New chip advances quantum optics research

Friday, April 13, 2012

A collaboration between IQC and the University of Toronto has led to a new chip that could greatly advance optical approaches to quantum information technologies.

A diagram of the waveguide chip tested at IQC
A new technology promises to enable practical, scalable quantum photonics — an important advance in quantum information research — thanks to joint research between IQC and the University of Toronto.

The technology, a waveguide chip developed at U of T and tested at IQC — can perform several crucial functions that typically require the bulky and expensive equipment of a quantum optics lab.

The chip enables a new method for creating a precious quantum resource — entangled pairs of photons of wavelengths useful for quantum information applications.

Until now, this process typically required large optical tables, expensive lasers, crystals beam-splitters and plenty of space.

The new chip can perform many of the same function of such labs, but in a scalable semiconductor architecture — an essential advance in the quest for practical quantum information devices. Future quantum computers and other quantum devices will likely be hybrids of several technologies, including optical elements such as the waveguide.

The team’s results were published this week in Physical Review Letters and was highlighted in a Focus article.

When shot with laser light, the gallium arsenide device churns out pairs of entangled photons at a high rate. The device generates a handful of entangled pairs for roughly every billion photons fired into it, which is a impressive ratio compared to other methods of creating entanglement with semiconductors.

Such a chip could be integral to the development of scalable photonics-based quantum computers and other quantum technologies, says IQC postdoctoral fellow Rolf Horn, who tested the chip with former IQC professor Gregor Weihs.

“It’s an important step in the development of integrated quantum photonics technologies, which will likely see many practical applications,” Horn said. “This is driving us closer to scalability and the creation of commercial quantum devices.”