In addition to twist, heterostrain can have important consequences on the electronic[2][3] and optical[4] properties of the resulting structure.
Recent works have reported a deterministic control of heterostrain by sample processing[7] or with the tip of an AFM[8] of particular interest in twisted heterostructures.
Heterostrain can be measured by scanning tunneling microscope which provides images showing both the atomic lattice of the first layer and the moiré superlattice.
[11] The method is immune to calibration artifacts which affect the image of the two layers identically which cancels out in the relative measurement.
It can result from a meta-stable configuration during bottom up assembly[1] or from the layer manipulation in the tear and stack technique.