Researchers manipulate quasiparticles to record data with light

13 Mar 2017

Concept illustration of quasiparticles. Image: sakkmesterke/Shutterstock

A team of European physicists might be on to a new generation of sensors, having forged quasiparticles that record data at room temperature.

Led by a team from ITMO University in Russia, researchers have made a substantial breakthrough in photonics that could allow us to record significant quantities of information using light.

In a new research paper published in Advanced Materials, the researchers revealed how, along with their European colleagues, they were able to generate quasiparticles (called excitons) capable of recording data using light at room temperature.

An exciton is a phenomenon within the mysterious world of quantum mechanics, whereby an ‘electron-hole’ pair provides energy transfer between photons and electrons.

For the past few years, the wider scientific community has been saying that this quasiparticle method will help to combine optics with electronics to create a fundamentally new class of data recording equipment, which is both smaller and more energy-efficient.

The only problem is that previous tests have shown exciton experiments have only operated at low temperatures and have been difficult to manufacture – until now.

To get them working at room temperature, the team led by Valentin Milichko found a method of controlling the quasiparticles with ultra-high sensitivity of hundreds of femtoseconds, as well as cracking an easy method for data recording with excitons.

Record data with the flick of a switch

One of the key reasons for this latest success stemmed from the use of an individual class of materials called metal-organic frameworks, with a layered crystal structure that uses an organic layer to prevent the others coming together.

With this knowledge, the researchers used the interlayer (where excitons are more stable), offering potential uses for recording data.

By changing the distance between the different layers, the ability to record data can be switched on and off.

“We locally heated the crystal with a laser,” said Milichko.

“In the place of exposure, the layers stuck together and the luminescence of excitons disappeared while the rest of the crystal continued shining. This could mean that we recorded one bit of information, and the record, in the form of a dark spot, was kept for many days.”

The research team believes this could be used to create compact optoelectronic devices for rapid recording and processing of optical signals.

Colm Gorey was a senior journalist with Silicon Republic