From valley qubits to many-body valley effects in 2D materials

Abstract:
Monolayer semiconducting transition-metal dichalcogenides (TMDs) form a unique platform for developing gated spin- or valleytronic devices due to their efficient gate tunability. Valley isospin can serve as a quantum information host in optically controlled devices but also in gate-defined quantum dots (QDs), that fulfill scalability criterion. In this talk I will shortly describe our theoretical predictions for electrically controlled nanostructures, starting from valleytronics in 2D materials, including devices to electrically store and manipulate valley qubits defined in QDs, but also coupled with states localized on defects. Next, I will explore new possibilities for defining qubits not only on K-valley degree of freedom active in TMD monolayers, but also using three Q-valleys, forming possible qutrit. Then I will try to investigate the interaction effects for valley hosts in gated nanostructures, showing that symmetry-broken valley polarized states can emerge only in a regime of strong interactions. I will supplement this with calculations of pair correlation function that reveal the valley-antiferromagnetic phase, and finally predict the possible formation of exotic Wigner-zigzag crystallization in valley-polarized liquids.