Nanotechnology Technology

New Compact Light Source Sends Large Amounts of Data


Researchers at the Hebrew University of Jerusalem have created a packed and highly proficient photon source that has the ability to operate on a chip. This single photon source shows promise in leading quantum information technology with a small, affordable and efficient futuristic solution.

Quantum information science and quantum information technology have created a much faster and secure way to communicate since the start of the 21st century. At the center of this quantum system is the quantum bit (also known as q bit) which carries all quantum information. Thus far, the best carrier of qbit as far as speed and distance has been the photon. This unit of light offers the best information transfers known to science.

Scientists have long been challenged by the attempt to take on many quantum information projects at the same time, and have been trying to build artificial sources that produce photons. The most difficult part of the whole process is finding a way to scale the photon sources down so they can be attached to a chip while also being able to survive room temperature. Photons typically only survive in temperatures of about -270C. Keeping the particles at such a drastic temperature proves to be very expensive in itself. Another concern is that artificial sources do not always emit photons in directions that can be expected, so collection is another tricky part of the process.

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Results of the experiment show that 20% of the photons are emitted into a very low numerical aperture (NA < 0.25), a 20-fold increase over a free-standing quantum dot, and with a possibility of more than 70% for a single photon emission. When NA = 0.65 more than 35% of the single photon emission is collected. (Image Credits: ACS)

A team of scientists at the Hebrew University of Jerusalem have come up with a compact single photon source that is able to operate in room temperature. With the help of tiny nanocrystals that were made of semiconducting materials, the scientists were able to take a single crystal and place it on top of a nano-antenna. After single photons are created by the nanocrystal, the nano-antenna works as a radio, calling photons to a specific location for easier capture. An optical setup allowed scientists to collect and analyze the particles thanks to single photon detectors.

The compound device not only offers collection efficiency by more than a factor of 10 but it also does not require heavy duty and complicated optical collection systems. About 40% of photons were collected during tests, with 20% of photons being emitted into a low numerical aperture. The probability was greater than 70% for photon emission.

This new antenna is made up of metallic and dielectric layers. These layers are compatible with industrial fabrication technologies used regularly today, all holding the ability to be built on top of a tiny chip. Currently, the team is designing a next generation of devices that should be able to allow production of photons to move directly from the chips and into optical fibers.

Professor Ronen Papaport from Racah Institute of Physics, the Department of Applied Physics and the Center of Nanoscience and Nanotechnology at Hebrew University says this new technology will have many uses within the world of quantum technology. There is a promise of higher purity and efficiency that was not possible in the past.

The study was published in the journal Nano Letters.