Effects of dynamical noises on Majorana bound states

TL;DR

This paper investigates how various dynamical noises affect the stability of Majorana bound states in topological superconductors, with implications for quantum computing robustness.

Contribution

It analyzes the impact of different dynamical noises on MBSs in both theoretical models and experimental systems, highlighting factors that enhance robustness.

Findings

Long-range pairings reduce transition rates of MBSs.

Low magnetic fields and strong spin-orbit coupling improve noise resilience.

Dynamical noises can significantly influence MBS stability in realistic systems.

Abstract

The nonlocal nature of unpaired Majorana bound states (MBSs) in topological superconductors can be exploited to create topologically protected qubits and perform gate operations fault-tolerantly via braidings. However, the time-dependent noises induced by coupling to an environment which is inevitable in any realistic system could spoil the topological protection. In this work, we study the effects of various dynamical noises such as Lorentzian, thermal, and quantum point contact on the MBSs in the recently proposed one-dimensional topological superconductors. We begin by investigating the Kitaev p-wave superconductors and examine the effects of long-range hopping and pairing on the transition rate of MBSs. We found that, especially, the long-range pairings significantly reduce the transition rate of bound states. Then, we consider the recently discovered topological superconducting nanowires and magnetic chains. Our findings are consequential for the recent attempts to manipulate MBSs. In particular, for the latter two experimentally realized systems we argue how low magnetic/Zeeman fields and strong spin-orbit coupling make the MBSs more robust to noises.