Multi-purpose photonic chip on silicon Electronics News

RESEARCHERS from the University of Bristol’s Centre for Quantum Photonics have developed a multi-purpose photonic chip, an important step toward programmable quantum processors.

The optical chip generates, manipulates and measures entanglement and mixture. According to the researchers, entanglement is a fundamental driver for quantum computing.

Entanglement is the connection between two distant particles. The Bristol researchers have, for the first time, shown that this phenomenon can be generated, manipulated and measured entirely on a tiny silica chip.

The chip can also measure mixture, which has traditionally been an unwanted effect from the environment, but which can now be controlled and used to characterise quantum circuits.

This development means that entanglement and mixture can be controlled on a chip which can be scaled and duplicated.

The chip, which performs several experiments that would each ordinarily be carried out on an optical bench the size of a large dining table, is 70 mm by 3 mm. It consists of a network of tiny channels which guide, manipulate and interact single photons.

Using eight reconfigurable electrodes embedded in the circuit, photon pairs can be manipulated and entangled, producing any possible entangled state of two photons or any mixed state of one photon.

The researchers are now working on scaling up the complexity of this device, and see this technology as the building block for the quantum computers of the future.

More information: ‘Generating, manipulating and measuring entanglement and mixture with a reconfigurable photonic circuit’ by P. J. Shadbolt, M. R. Verde, A. Peruzzo, A. Politi, A. Laing, M. Lobino, J. C. F. Matthews, M. G. Thompson and J. L. O'Brien in Nature Photonics

Multi-purpose photonic chip on silicon Electronics News