Dimensional crossover in spin-orbit-coupled semiconductor nanowires with   induced superconducting pairing
  We show that the topological Majorana modes in nanowires much longer than the superconducting coherence length are adiabatically connected with discrete zero-energy states generically occurring in short nanowires. We demonstrate that these zero-energy crossings can be tuned by an external magnetic field and are protected by the particle-hole symmetry. We study the evolution of the low-energy spectrum and the splitting oscillations as a function of magnetic field, wire length, and chemical potential, manifestly establishing that the low-energy physics of short wires is related to that occurring in long wires. This physics, which represents a hallmark of spinless p-wave superconductivity, can be observed in tunneling conductance measurements. 
Tudor D. Stanescu, Roman M. Lutchyn and S. Das Sarma
cond-mat.supr-con cond-mat.mes-hall