Interlayer excitons in the heterostrain induced moire of heterobilayer transition metal dichalcogenides

Here we investigate the optical properties of interlayer excitons in heterobilayer transition metal dichalcogenides where moire pattern is introduced by the uniaxial heterostrain, in comparison with that introduced by twisting. Besides being a cause of the moire texture, the uniaxial strain also effectively introduces a constant gauge potential on carriers, which results in distinct exciton mini-band dispersions from the twisting induced moire, even though the excitonic superlattice potential can have the same real space profile for the two cases. As the uniaxial strain breaks the three-fold rotational symmetry, the exciton wavepackets trapped at the superlattice potential minima now have elliptically polarized valley optical selection rule, in contrast to the circularly polarized ones in the twisting moire. We investigate the evolution of the excitonic mini-bands and the optical dipoles of the states inside the light cones with the change of the moire periodicity.