A technology company in Dubai has helped to illuminate "an enigma" in the world of physics by uncovering how two types of crystals interact with light.
Scientists at XPANCEO, in Dubai Internet City, collaborated with Prof Kostya Novoselov, a Russian-British academic, to reveal unique properties that could prove useful for diagnosing illnesses such as cancer and developing faster computers.
Prof Novoselov, who works at the University of Manchester in the UK and the National University of Singapore, won the 2010 Nobel Prize in Physics for work on graphene, a type of carbon in which the atoms are arranged in a hexagonal shape.
Published in the Nature Communications journal on Wednesday, his latest research concerns crystals of two chemicals called rhenium diselenide and rhenium disulfide.
While graphene is known for its remarkable strength and lightness – it is much stronger than steel, but lighter than aluminium – the two substances analysed in the new study are notable because of how they interact with light.
"It required a lot of effort from the theory and experimental part," said Dr Valentyn Volkov, co-founder of XPANCEO and one of the authors of the study.
"There’s a big difference between this and traditional layered crystals. It was clear that this unusual and unique material should possess properties which are not very usual for solid optical materials. That was our main motivation – to dig in this direction and see what surprises came out."
Most layered crystals are symmetrical, so in all directions – in three dimensions – they are the same.
Breaking new ground
The two substances described in the latest study are notable because they are asymmetrical, so the position of atoms in all three dimensions is different. Such crystals are called triclinic.
The researchers aimed to find out what effects this asymmetry has on how the crystals interact with light.
"Before we started experiments, we usually study the scientific literature to know what’s already been done," Dr Volkov said.
"It was clear that this field was a kind of enigma. People didn’t really try to investigate these triclinic materials with high precision. Nothing was really done in this field."
What makes the properties of the crystals unique is that if the wavelength of light shone on them is changed, the direction in which the light spreads is deflected within the crystal. This is, Dr Volkov said, an "absolutely unique" property.
What next?
It could be useful in areas of technology including electronics, where light is used to send energy and information.
Light is a particularly good medium for sending energy or information, Dr Volkov said, because, unlike electrons, light does not have any mass.
"This discovery allows you to manipulate light not by changing the material itself, but by changing the properties of the light," he said. "It’s an additional level of freedom and opens up new and unique possibilities for making compact and novel optoelectronic devices.
"Our human species is always looking for new methods to control light. These new materials are already a significant step towards new mechanisms to control light."
The crystals could be used to help develop more powerful, heat-resistant computers for areas such as machine learning or artificial intelligence.
Another potential application is in the development of biochemical sensors to detect viruses or diseases including cancer at an earlier stage. They could also be used to develop cheaper and more accurate blood tests.
The study is co-written by eight of Dr Volkov’s colleagues at XPANCEO, along with researchers in Singapore, Spain and Switzerland.
The research by XPANCEO on rhenium diselenide and rhenium disulfide ties in with the company’s work to develop smart contact lenses that, the company said, can be used for a variety of applications, extending even to monitoring a person’s health.
