We know the three most common aggregates of matter – solid, liquid and gaseous. Additionally there is a fourth, less common form – plasma. In addition, there is a completely new state of the substance – “superficial”, which scientists discovered a few years ago, and in the present study, according to a report published in the journal Nature, for the first time in history it was taken in two-dimensional form.
It should be noted that the superimposed state is not an enhanced, or higher density version of the solid. In this state, matter is solid, with atoms, like ordinary solids, arranged in crystalline structures, although the difference is that, like the supernatant, the surface can flow at zero velocity – at first glance, the simultaneous possession of these two properties sounds paradoxical.
Scientists have been considering the possibility of such a condition since the 1960s, and in 2017 its existence was experimentally proven – MIT researchers were able to obtain it by combining the properties of solid and supernatant states.
In the present study, several teams of researchers combined their resources to create a superficial substance with the help of other states of matter such as Bose-Einstein condensate. The latter is the fifth aggregate state – a low-density gas cloud whose temperature is close to absolute zero (-273.15 ° C). In this state, particles exhibit quantum properties that are not observed on a relatively macro scale. In Bose-Einstein condensate, at such a low temperature, each particle is delocalized, which means that they exist simultaneously at all points in the cloud at any point in time.
In early experiments, scientists created superficial substances that existed in only one dimension – they could only flow in one direction. But, a team of researchers from the University of Innsbruck took this condition in an additional one dimension as part of a new study. The Bose-Einstein condensate was formed from the atoms of the dysprosium – under the influence of magnetic interactions between atoms, they split into regions of high density and form a lattice.
“Under normal circumstances, these atoms would fall into any specific droplets, including without a chance of getting hit,” study author Matthew Norchia told the New Atlas. “However, in the superficial state, each particle is delocalized and they exist in all droplets at the same time. So we got a system with high density regions (droplets) that share delocalized atoms,” he added.
The team of researchers also noted that this achievement might allow physicists to study a whole new range of quantum properties and to observe the properties of particles that they could not observe in a single dimension. For example, how the vortices between the drops rotate in a two-dimensional surface system. “The vortices that have been described theoretically have not been shown experimentally yet, although they are an important result of the supremacy”