Universal properties of disordered electron nematics from surface probes

When the electronic degrees of freedom break the rotational symmetry of the host crystal, i.e. from C$_4$ to C$_2$, the resulting state is an electronic Ising nematic. However the combination of reduced dimensionality and material disorder can forbid the formation of a long- range-ordered electron nematic, especially in strongly layered materials. Nevertheless, large domains are still possible. In this talk we will present results from a new kind of analysis for Scanning Tunneling Microscopy (STM) experiments as well as other surface probes. We map the locally broken C$_4$ to C$_2$ rotational symmetry of the electronic degrees of freedom to an Ising-type order parameter,use the local order parameter configuration to shed light on the universality class controlling the local pattern formation in cuprate superconductors.