Reusing existing fiber optic infrastructure is (almost) as big a deal as it gets.

By Francisco Pires

A render for a single T centre qubit in the silicon lattice, which supports the first single spin to ever be optically observed in silicon. The constituents of the T centre (two carbon atoms and a hydrogen atom) are shown as orange, and the optically-addressable electron spin is in shining pale blue. (Image credit: Photonics)

Researchers from Simon Fraser University may have just released the photonic springs that accelerate the quantum internet. In a paper published in Nature, the researchers demonstrated an emergent capacity in silicon qubits to produce a “photonic link” between each other. Furthermore, this same photonic capability may be easily integrated with the existing fiber optic infrastructure that already carries data across a reasonable (yet still insufficient) portion of society. That is bound to provide immense savings on deploying a quantum internet – and as we all know, the cost is (mostly) king.

The authors’ paper describes observations carried on particular types of qubits: “T-center” photon-spin qubits, a kind of qubit that takes advantage of a specific luminescent defect in silicon – more specifically, InGaAs (Indium gallium arsenide), also explored in CPU manufacturing technologies. Silicon qubits have already shown remarkable coherence times – which relate to how resistant qubits are to outside interferences that would cause them to collapse and lose their information in the process, becoming unusable for the workload at hand.

And with more fantastic coherence times – and the comparative ease with which these “T center” qubits can be linked – comes the capability to perform more and more significant calculations. In their experiment, the researchers observed the effect in over 1,500 T Center qubits, ensuring they can replicate it – a healthy indicator for the potential scalability of their solution.

“This work is the first measurement of single T centers in isolation, and actually, the first measurement of any single spin in silicon to be performed with only optical measurements,” said Stephanie Simmons, Canada Research Chair in Silicon Quantum Technologies.  

“An emitter like the T center that combines high-performance spin qubits and optical photon generation is ideal to make scalable, distributed, quantum computers,” she continued, “because they can handle the processing and the communications together, rather than needing to interface two different quantum technologies, one for processing and one for communications.”

Continue reading… “Breakthrough in Silicon Qubits, Photonics Accelerates Quantum Internet”