Tuesday, August 9, 2022

Scientists found the missing photonic link to enable an all-silicon quantum internet

An important milestone that unlocks immediate opportunities to construct massively scalable quantum computers.

The global quantum internet will require long-lived, telecommunications-band photon–matter interfaces manufactured at scale. It is essential to develop the communications technology that enables these qubits to link together at scale and stable, long-lived qubits that supply processing power to make this a reality.

A study has indicated that silicon can produce some of the most stable and long-lived qubits. Despite the overwhelming potential of the silicon quantum platform, the optical detection of individually addressable photon–spin interfaces in silicon has remained elusive. In a new study, scientists offer proof of the principle that T centers, a specific luminescent defect in silicon, can provide a ‘photonic link’ between qubits.

Stephanie Simmons, Department of Physics, Simon Fraser University, Burnaby, British Columbia, Canada, said, “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.”

“An emitter like the T center that combines high-performance spin qubits and optical photon generation is ideal for making scalable, distributed, quantum computers 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.”

“In addition, T centers have the advantage of emitting light at the same wavelength today’s metropolitan fiber communications and telecom networking equipment use. With T centers, you can build quantum processors that communicate with other processors. When your silicon qubit can communicate by emitting photons (light) in the same band used in data centers and fiber networks, you get these same benefits for connecting the millions of qubits needed for quantum computing.”

Silicon-based quantum technology development offers chances for quickly scaling quantum computing. The world’s semiconductor industry is already capable of mass-producing silicon computer chips at low cost and with astonishing levels of accuracy. From cell phones to the most powerful supercomputers in the world, this technology is the foundation of modern networking and computing.

Simmons said“By finding a way to create quantum computing processors in silicon, you can take advantage of all of the years of development, knowledge, and infrastructure used to manufacture conventional computers, rather than to create a whole new industry for quantum manufacturing. This represents an almost insurmountable competitive advantage in the international race for a quantum computer.”

Journal Reference:

  1. Higginbottom, D.B., Kurkjian, A.T.K., Chartrand, C. et al. Optical observation of single spins in silicon. Nature 607, 266–270 (2022). DOI: 10.1038/s41586-022-04821-y

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