2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/16134Recent Scanning Tunneling Microscope (STM) experiments offer a unique insight into the inner workings of the superconducting state of high-Tc superconductors. Deliberately placed inside the material impurities perturb the coherent state and produce additional excitations. Superconducting excitations - quasiparticles - are the quantum mechanical mixture of negatively charged electron (-e) and positively charged hole (+e). Depending on the applied voltage bias in STM one can sample the particle and hole content of a superconducting excitation. We argue that the complimentary cross-shaped patterns observed on the positive and negative biases are the manifestation of the particle-hole dualism of the quasiparticles.4 pages, 4 eps figuresSuperconductivityDisordered Systems and Neural Networkstext