Physicists have observed, in a topological insulator at room temperature, quantum effects that until now were possible only very close to the lowest temperature allowed by the laws of physics.
This breakthrough came when a team made up of, among others, Nana Shumiya and M. Zahid Hasan, from Princeton University in the United States, explored a new topological material based on the element bismuth.
Topological insulators, a class of exotic materials widely used in quantum research, act as insulators within themselves, meaning that the electrons inside them are not free to move and therefore do not conduct electricity. However, the electrons at the edges of the insulator are free to move, which means that the edges are conductors. Furthermore, due to the special properties of the topology, the electrons flowing around the edges are not hampered by any defects or deformations. Topological insulators have important potential utilities in quantum technologies. And they can also help to gain new and revealing insights into the quantum behavior of matter.
Until now, however, the only known topological insulators were those that function at temperatures very close to absolute zero (273 degrees Celsius below zero, the lowest temperature allowed by the laws of physics). The requirement of having to keep these materials at such low temperatures greatly limited their use in practical applications, considering how expensive and cumbersome such extreme cooling is.
The new topological insulator is an inorganic crystalline compound made from bismuth bromide.
The new topological insulator, made from the elements bismuth and bromine, exhibits specialized quantum behaviors normally only seen under extreme experimental conditions that include temperatures near absolute zero. (Image: Shafayat Hossain / M. Zahid Hasan / Princeton University)
This finding opens up a new range of possibilities for the development of efficient quantum technologies, such as spin-based electronics (spintronics), which could replace many current electronic systems to achieve greater energy efficiency.
Shumiya and his colleagues present the technical details of their achievement in the academic journal Nature Materials, under the title “Evidence of a room-temperature quantum spin Hall edge state in a higher-order topological insulator.” (Font: NCYT by Amazings)