Microscopic evidence for the intra-unit-cell electronic nematicity inside the pseudogap phase in YBa${}_2$Cu${}_4$O${}_8$

W. Wang, J. Luo, C. G. Wang +4

Understanding the nature of the mysterious pseudogap phenomenon is one of the most important issues associated with cuprate high-$T_c$ superconductors. Here, we report ${}^{17}$O nuc…