Fig. 2: Excitation of QLMs through infinitesimal external strain.

a–e Illustration of a glass sample with a QLM (ω =  0.154, PR =  0.050) oriented close to 45^∘. a Eigenvector field of the QLM. b Non-affine displacement field under athermal quasistatic shear deformation along the positive direction of the horizontal axis. d provides an enlarged view of the central region from (b). c Non-affine displacement field under reversed shear direction. e provides an enlarged view of the central region from (c). Note that vector directions in (d, e) are opposite. Importantly, uniaxial tension and compression do not excite this QLM under similar conditions. f–j Illustration of another glass sample with a QLM (ω  =  0.150, PR  =  0.013) oriented close to 90^∘. f Eigenvector field of the QLM. g Non-affine displacement field under athermal quasistatic tension along the horizontal axis. i provides an enlarged view of the central region from (g). h Non-affine displacement field under athermal quasistatic compression along the horizontal axis. j provides an enlarged view of the central region from (h). Note that the vector directions in (i, j) are opposite. We confirm that simple shear cannot excite this QLM under similar conditions.