Designing XY and Dzyaloshinskii-Moriya couplings in Majorana Cooper pair boxes
Phys. Rev. B 114, 274505 – Published 9 November, 2026
DOI: https://doi.org/10.1103/n3mw-w3zg
Abstract
We theoretically study how to design spin couplings in networks of Majorana Cooper pair boxes (MCBs) connected by multiple normal-metal leads. The interbox interaction is generated by the conduction-electron-mediated Ruderman-Kittel-Kasuya-Yosida interaction. We show that the connectivity of Majoranas to the leads enables arbitrary types of couplings. As concrete examples, we show the realization of the XY and Dzyaloshinskii-Moriya couplings, which are difficult to implement in previously proposed MCB-based schemes. The sign and magnitude of the couplings can be tuned continuously via gate-controlled tunneling amplitudes. These results establish MCBs as a versatile platform for engineered quantum spin systems.
