CHESS (Cornell High Energy Synchrotron Source)

CHESS is the Cornell High Energy Synchrotron Source. The source digest links a CHESS write-up by Elke Arenholz titled "Spontaneous Gyrotropic Electronic Order in 1T-TiSe₂," which summarizes the 2020 Nature result by Su-Yang Xu et al. and attributes the work to a team led by Nuh Gedik's group at mit.

The CHESS summary describes the measurement technique used — the Circular Photogalvanic Effect, in which a change in photocurrent is measured when the helicity of light is flipped, which can only occur if the electrons in the material are chiral — and presents the result as spontaneous chiral symmetry breaking by electrons in 1T-TiSe₂ despite its non-chiral crystal structure.