Researchers stumbled upon new matter when studying nanomaterials

Materials World magazine
1 Apr 2020

A new state of matter was found when studying 2D materials. Idha Valeur finds out what it could mean for science. 

While experimenting with two 2D nanomaterials – bismuth selenide and dichalcogenide – scientists at Northeastern University, USA, observed the electrons behaving unusually.

Instead of repelling each other as expected due to their negative charge, the electrons formed a stationary pattern at room temperature. ‘We believe we have discovered evidence of a purely electronic 2D lattice that resides at the interface of two different types of 2D materials,’ Northeastern University, Associate Professor in Physics, Swastik Kar, told Materials World. ‘These appear to be periodic arrays of electronic charges that float in the physical space in between the two 2D crystal planes.’ 

According to Kar, being able to stabilise only electrons into a crystal has been an incredibly difficult task for the physics community, but some researchers have claimed that their work has demonstrated these conditions at ultra-low temperatures. ‘Even if that were true, it makes it extremely difficult to perform additional experiments on the low-temperature systems, or build applications based on them. In this context, the electronic lattice we have seen evidence of forms readily at room temperature, making them available not only for a wide range of experimental approaches, but also for realistic applications,’ he said.           
To avoid making unprecedented claims, Kar would only give educated estimations rather than shock predictions. ‘An array of purely electronic charges in two dimensions is a state of matter like nothing else we know, and we are fairly excited by their scientific potentials.If we can design experiments that can directly probe this layer, e.g. by attaching electrodes, it could potentially lead to a new chapter in the physics of quantum transport phenomena,’ he said. ‘Electron-transport along any purely charged lattice could possibly remain protected from scattering, leading to large-scale charge and spin coherence, room and low-temperature magneto-transport, and optoelectronic behaviour.’ 

In response to people reaching out asking whether it could lead to a new type of superconductivity, Kar emphasised that his team are eager to investigate and assess this aspect. He added that these materials could be of interest and benefit to scientists in various fields, including electrical engineering, photovoltaics, sensing and detection sciences, and communications.  

Going forward, the team will continue its exploration of these materials, ‘and actively seek collaborations with other experts who can force-multiply the impact of this discovery,’ Kar said. ‘The challenge for early-stage research is to grow quickly.’