We investigate the elastic normal modes of two-dimensional media with broken time-reversal and parity symmetries due to a Lorentz term. Our starting point is an elasticity theory that captures low-energy physics diverse range systems such as gyroscopic metamaterials, skyrmion lattices in thin-film chiral magnets certain Wigner crystals. By focusing on circular disk geometry we analyze finite-si...

The use of lasers for generating and detecting ultrasound is becoming more established in non-destructive testing. However, there is still scope in developing the techniques to fully realise the benefits of non-contact measurements. One application is the detection of surface defects in metals; for example, rolling contact fatigue in rails, and surface cracking on billets or plates. We present ...