Tunable Majorana networks based on second-order topological superconductors

Second-order topological superconductors (SOTSs) host localized Majorana fermions and represent a novel platform to study and exploit the properties of these non-Abelian anyons. We propose a way to realize networks based on SOTSs which allow to nucleate and braid Majorana bound states (MBSs) in an all-electrical manner, without fine-tuning. The proposed setups are scalable and can accommodate any even number of MBSs. Moreover, the MBSs in the networks allow defining qubits whose states can be initialized and read out by measuring Josephson currents flowing between SOTS islands. Our proposal can be implemented, for example, in monolayers of FeTe1−xSex, monolayers of 1T’-WTe2, and inverted Hg(Cd)Te quantum wells in proximity to conventional superconductors