Weyl points in systems of multiple semiconductor-superconductor quantum dots

Abstract

As an analogy to the Weyl point in k-space, we search for energy levels which close at a single point as a function of a three-dimensional parameter space. Such points are topologically protected in the sense that any perturbation which acts on the two-level subsystem can be corrected by tuning the control parameters. We find that parameter-controlled Weyl points are ubiquitous in semiconductor-superconductor quantum dots and that they are deeply related to Majorana zero modes. In this paper, we present several semiconductor-superconductor quantum-dot devices which host parameter-controlled Weyl points. Furthermore, we show how these points can be observed experimentally via conductance measurements.