Graphene as a possible quantum material for computers
One of the most intriguing phenomena in condensed matter physics is the fractional quantum Hall effect, an exotic electronic state with phases appearing to have the right properties for building a topological quantum computer. It is a property of a collective state in which electrons bind magnetic flux lines to make new quasiparticles, and excitations have a fractional elementary charge and possibly also fractional statistics. Recent studies have reported evidence of fractional quantum Hall effect in graphene, rendering it suitable for fast quantum computing devices. Graphene is an extraordinary 2D material exhibiting unique and surprising many-body effects resulting from strong electron interactions. Spurred by its potential in future electronic technologies, scientists initiated the project EXOTICPHASES4QIT (Exotic quantum phases in graphene and other modern nanomaterials - Physical foundation for quantum information technology). The team implemented powerful computational methods to model electronic structure and many-body effects in nano-structured graphene of particular shape and type of edge. The aim was to study emergence of exotic electronic phases. The scientists also conducted comparative studies of the fractional quantum Hall effect in graphene and conventional semiconductors. Results offer further insight into the magnetic properties of many-electron graphene nanostructures and reveal the role of pseudospin degeneracy and different interaction pseudopotentials in semiconductors. Scientists also developed a model to describe spin and pseudospins in fractional quantum Hall systems. These included composite fermions – bound states of electrons and many-electron vortices – that carried fractional charges and exhibited non-Abelian quantum statistics. The model also enabled scientists to enrich understanding of the incompressibility of several fractional quantum Hall states for filling factors 3/8 and 4/11. EXOTICPHASES4QIT resulted in 15 publications in high-impact-factor international journals and 7 conference lecture invitations.
Keywords
Graphene, quantum computers, exotic states, fractional quantum Hall effect, many-body effects
