In-plane Isotropy of the Low Energy Phonon Anomalies in YBa${}_2$Cu${}_3$O${}_{6+x}$

Sofia-Michaela Souliou, Kaushik Sen, Rolf Heid +8

We study the temperature dependence of the low energy phonons in the $(H,0,L)$ reciprocal plane of the highly ordered ortho-II YBa${}_2$Cu${}_3$O${}_{6.55}$ cuprate high temperature su…