Tunable moiré potentials in 2D-heterostructures using anisotropic strain

Principal investigators

  1. Jonathan J. Finley, Walter Schottky Institut & TU-München, finley (at) wsi.tum.de [webpage]
  2. Fei Ding, Leibniz Universität Hannover, f.ding (at) fkp.uni-hannover.de [webpage]
  3. Rolf Haug, Leibniz Universität Hannover, haug (at) nano.uni.hannover.de [webpage]

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Abstract

This project focuses on the exploration of strongly correlated electronic and excitonic phases in strain tuneable van der Waals heterostructures formed from graphene and transition metal dichalcogenides. We probe strongly correlated quantum states in strain-tuneable moiré superlattices as a function of particle (electron, exciton, trion) density, lattice temperature and the presence of energy input (driving). Experiments aim at elucidating equilibrium phenomena (correlation effects and condensation), testing the strength of inter-particle interactions, measuring the spectrum of low-lying excitations and assessing the impact of driving away from equilibrium.

The principle technical advance that exploited in this project is the controlled application of arbitrary (uniaxial, biaxial and anisotropic) strain for the in-situ control of the periodicity and symmetry of the moiré potential in vdW heterostructures. Strain tunable heterostructures are probed using highly local optical methods, having high spatial (<1µm) and temporal (~1ps) resolution, with non-local quantum (magneto-)transport approaches.