Gate-defined wires in HgTe quantum wells as a robust Majorana platform

We propose a new quasi-1D platform for Majorana zero-modes based on gate-defined wires in HgTe. Due to the Dirac-like band structure for HgTe such wires exhibit several remarkable properties. Most strikingly, modest gate-tuning allows one to modulate the Rashba spin-orbit energy from zero up to $\sim30K$, and the effective g-factor from zero up to giant values of $\sim600$. The large achievable spin-orbit coupling and g-factor together allow one to access Majorana modes in this setting at exceptionally low magnetic fields while maintaining robustness against disorder. Moreover, gate-defined wires may facilitate the fabrication of networks required for realizing non-Abelian statistics and quantum information devices. The exquisite tunablity of parameters further suggests applications in spintronics.