IIT-Bombay team looks for a way to encode, process and store quantum information at less-restrictive temperatures

Quantum computers are hot today, because of their mind boggling computing capacity that can better the best of existing supercomputers. They use the quantum phenomenon of superposition. However, quantum phenomena do not work at room temperature. Existing quantum computers, such as those of Google, IBM, and Microsoft, have to be kept at ultra-low temperatures of –196.1°C , making them costly and impractical.

Researchers at IIT-Bombay have used an emerging science, called ‘valleytronics’, to pave the way for ‘room temperature quantum computers’. Valleytronics is the study of location of electrons — the valleys refer to the local minima in the ‘conduction’ energy bands (the range of energy an electron needs to fly away from the atom).

“Valleys can be used to encode, process and store quantum information at less-restrictive temperatures,” notes an article presented by IIT-Bombay.

A team of its scientists, working in collaboration with the German Max-Born Institut, have used graphene for this. Prof Gopal Dixit, who led the research, says: “By tailoring the polarisation of two beams of light according to graphene’s triangular lattice, we found it possible to break the symmetry between two neighbouring carbon atoms and exploit the electronic band structure in the regions close to the valleys, inducing valley polarisation.” In other words, this enables the use of graphene’s valleys to effectively “write” information. Conducting valley operations in graphene is possible at room temperature.