Scientists create quantum entanglement on a silicon chip

A team of scientists has figured out a way for a standard silicon chip to tackle quantum entanglement — a phenomenon in which multiple particles are connected to each other and act in uniform, regardless of how far apart they are. The scientists’ findings were detailed on Monday in a research paper published in Optica, a monthly journal by The Optical Society (OSA).

So far, harnessing the power of quantum entanglement onto silicon chips has proven to be a difficult task because of the large size of the devices used to emit entangled photons; photons are essentially the particles that make up light. Creating silicon chips — which are inexpensive and prevalent compared to specialized entanglement equipment — that can handle quantum entanglement is a big deal in that it can allow for more powerful computer chips and better encryption technology.

The researchers of Università degli Studi di Pavia in Italy have come up with a way to solve this problem by creating a microscopic device that can supposedly fit onto a silicon chip and produce entangled photons.

The researchers paired a silicon wafer with what’s known as a ring resonator — a closed loop that photons enter on one side via a laser beam. They emerge entangled on the other side, where they are captured.

According to the research paper, the team of scientists was able to “demonstrate that silicon ring resonators in a silicon-on-insulator platform are an efficient source of time-energy entangled photon pairs.”

From the research paper:
[blockquote person=”” attribution=””]We can confidently expect that silicon mircoring resonators will become the dominant paradigm of correlated photon sources for quantum photonics, both for applications involving the transmission of quantum correlations over long distances, such as quantum cryptography, and for applications involving quantum information processing “on-a-chip.”[/blockquote]

Quantum entanglement can be very useful to the field of security and can help with encrypting messages. GridCOM Technologies, for example, explained to Gigaom in 2013 that it uses quantum entangled photons to generate encryption keys.

Any time someone tries to measure an entangled photon to learn what it may have encrypted, the GridCOM system is automatically pinged because of the way the photons are connected; each entangled particle affects the other and when one particle exists in a state where it is spinning up, its correlated particle will take on a state where it is spinning down.