Strain-Controlled Atomic Reconstruction and Quasi-1D Excitons in Moiré Heterostructures

In two-dimensional materials, strain provides effective means for tailoring electronic and optical properties. While uni- or biaxial strain has been widely implemented in monolayer semiconductors, deterministic control over atomic reconstruction and the resulting microscopic stacking textures in moiré heterostructures remains challenging. Here, we demonstrate the controlled formation of one-dimensional quantum wire arrays in <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mrow> <a:mrow> <a:msub> <a:mrow> <a:mi>MoSe</a:mi> </a:mrow> <a:mrow> <a:mn>2</a:mn> </a:mrow> </a:msub> </a:mrow> <a:mtext>−</a:mtext> <a:msub> <a:mrow> <a:mtext>WSe</a:mtext> </a:mrow> <a:mrow> <a:mn>2</a:mn> </a:mrow> </a:msub> </a:mrow> </a:math> heterobilayers through the interplay of uniaxial strain and atomic reconstruction. This process yields one-dimensional confinement of interlayer excitons within domain walls, producing near-unity linearly polarized emission due to confinement-induced symmetry breaking. The domain wall width and thereby the degree of exciton confinement can be precisely tuned via the interlayer twist angle. Under an out-of-plane electric field, the confined excitons exhibit Stark shifts exceeding 100 meV and fine-structure splitting modulations by up to a factor of 2. These findings establish strain tuning as a powerful route to realize designer moiré systems with programmable quantum properties, opening new opportunities for optoelectronic applications.