Non-abelian Majoranas and braiding in inhomogeneous spin ladders

Fabio L. Pedrocchi [1], Suhas Gangadharaiah [1,2], Stefano Chesi [3], and Daniel Loss [1]

[1] Department of Physics, University of Basel, Switzerland
[2] Indian Institute of Science Education and Research, Bhopal, India
[3] Department of Physics, McGill University, Montreal, Quebec, Canada

We propose an inhomogeneous open spin ladder, related to the Kitaev honeycomb model, which can be tuned between topological and non-topological phases. In extension of Lieb's theorem, we show numerically that the ground state of the spin ladder is either vortex-free or vortex-full. At the phase-boundaries single Majorana states emerge which are proven to be robust against local perturbations and to obey non-abelian braiding statistics. We show that a network of such spin ladders provides a promising platform for topological quantum computing.