The article by C. W. J. Beenakker discusses the search for Majorana fermions in superconductors, which are particles that are their own antiparticles. These fermions can be constructed from electron and hole excitations in condensed matter systems, particularly in topological superconductors. The key requirements for creating Majorana fermions include a superconductor to hide the charge difference and a topological phase to eliminate the energy difference from zero-point motion. A pair of widely separated Majorana fermions bound to magnetic or electrostatic defects exhibit non-Abelian exchange statistics, which could be used to create qubits with unusually long coherence times. The article reviews strategies for detecting Majorana fermions in topological superconductors, including half-integer conductance quantization, nonlocal tunneling, the 4π-periodic Josephson effect, and thermal metal-insulator transitions. It also explores potential applications in quantum computing, such as topological qubits, readout techniques, and braiding operations. Experimental progress is highlighted, including observations of the Josephson effect at the surface of 3D topological insulators and the detection of a Majorana zero-mode in an InSb nanowire. The article concludes by discussing the future prospects for experimental demonstrations of Majorana fermions and their potential impact on quantum computing.The article by C. W. J. Beenakker discusses the search for Majorana fermions in superconductors, which are particles that are their own antiparticles. These fermions can be constructed from electron and hole excitations in condensed matter systems, particularly in topological superconductors. The key requirements for creating Majorana fermions include a superconductor to hide the charge difference and a topological phase to eliminate the energy difference from zero-point motion. A pair of widely separated Majorana fermions bound to magnetic or electrostatic defects exhibit non-Abelian exchange statistics, which could be used to create qubits with unusually long coherence times. The article reviews strategies for detecting Majorana fermions in topological superconductors, including half-integer conductance quantization, nonlocal tunneling, the 4π-periodic Josephson effect, and thermal metal-insulator transitions. It also explores potential applications in quantum computing, such as topological qubits, readout techniques, and braiding operations. Experimental progress is highlighted, including observations of the Josephson effect at the surface of 3D topological insulators and the detection of a Majorana zero-mode in an InSb nanowire. The article concludes by discussing the future prospects for experimental demonstrations of Majorana fermions and their potential impact on quantum computing.