Photonic chips being developed for fault tolerant quantum computing
Xanadu, a full-stack photonic quantum computing company and imec have announced a partnership to develop the next generation of photonic qubits based on ultra-low loss silicon nitride (SiN) waveguides.
Based in Toronto, Canada, Xanadu is developing a unique type of quantum computer, one based on photonics. Specifically, these photonic qubits are based on squeezed states – a special type of light generated by chip-integrated silicon photonic devices.
This approach uses particles of light to carry information through photonic chips, rather than electrons or ions as used in other approaches. Xanadu’s photonic approach offers a number of benefits including: scalability to one million qubits via optical networking, room temperature computation, and the natural ability to leverage fabrication R&D centres such as imec.
“One of the most critical challenges in building a photonic quantum computer is finding the right fabrication partner that can simultaneously deliver cutting-edge process development and volume production of high performing photonic chips,” said Zachary Vernon, who heads up Xanadu’s Hardware team. “Imec is one of the few Semiconductor R&D centres that does advanced technology R&D on advanced 200mm and 300mm lines, as well as volume manufacturing on their 200mm line, capable of delivering up to a thousand wafers per year per customer on a few platforms including ultralow-loss photonic platforms. The seamless transfer offered by imec of new processes to production is especially critical for rapid scaling of our technology.”
Competing platforms for photonic quantum computing traditionally rely on single photon sources made from silicon waveguides, which suffer from non-deterministic operation.
By using silicon nitride it is possible to enable the generation of squeezed states, which replace single photons as the basic resource for synthesizing qubits. Squeezed states are deterministically generated, and can be used to distill error-resistant qubits called ‘GKP states’. When multiplexed and implemented in Xanadu’s architecture, these offer a more promising path to fault-tolerant quantum computing.
Commenting Amin Abbasi, business development manager at imec said, “We are pleased to see that imec’s wafer-scale low loss SiN photonics platform, initially developed for communication, is finding its way towards other advanced applications, like quantum computing. We look forward to working with Xanadu to drive further development of this platform for their particular needs.”
“Xanadu’s ultimate mission is to build quantum computers that are useful and available to people everywhere. To do this we have the ambitious goal of reaching one million qubits using photonics. Working with imec will help us build the right foundation based on fault tolerance and error-correctable qubits,” said Christian Weedbrook, Xanadu Founder and CEO.
Xanadu offers cloud access to both photonic quantum hardware and software solutions over its Xanadu Cloud platform. It recently announced a $100m round led by Bessemer Venture Partners giving a total of $145m raised to date.