# “Kerr effect as evidence of gyrotropic order in the cuprates ” presented by Srinivas Raghu (Stanford University)

Date:
Thursday, December 13, 2012 - 4:00pm to 5:00pm
Series:
Condensed Matter Physics Seminar in PAB 4-330

The Kerr effect can arise in a time-reversal invariant dissipative medium that is gyrotropic'', {\it i.e.} one that breaks inversion ($\mathcal I$) and all mirror symmetries. Examples of such systems include electron analogs of cholesteric liquid crystals, and their descendants, such as systems with chiral charge ordering. We present arguments that the striking Kerr onset seen in the pseudogap phase of a large number of cuprate high temperature superconductors is evidence of chiral charge ordering. We discuss additional experimental consequences of a phase transition to a gyrotropic state, including the appearance of a zero field Nernst effect.