Measuring Majorana fermions qubit state and non-Abelian braiding statistics in quenched inhomogeneous spin ladders

We study the Majorana fermions (MFs) in a spin ladder model. We propose and numerically show that the MFs qubit state can be read out by measuring the fusion excitation in the quenched inhomogeneous spin ladders. Moreover, we construct an exactly solvable T-junction spin ladder model, which can be used to implement braiding operations of MFs. With the braiding processes simulated numerically as non-equilibrium quench processes, we verify that the MFs in our spin ladder model obey the non-Abelian braiding statistics. Our scheme not only provides a promising platform to study the exotic properties of MFs, but also has broad range of applications in topological quantum computation.Comment: 5+3 pages, 6 figure

Distinct Spin Liquids and their Transitions in Spin-1/2 XXZ Kagome Antiferromagnets

By using the density matrix renormalization group, we study the spin-liquid phases of spin-$1/2$ XXZ kagome antiferromagnets. We find that the emergence of spin liquid phase does not depend on the anisotropy of the XXZ interaction. In particular, the two extreme limits---Ising (strong $S^z$ interaction) and XY (zero $S^z$ interaction)---host the same spin-liquid phases as the isotropic Heisenberg model. Both the time-reversal-invariant spin liquid and the chiral spin liquid with spontaneous time-reversal symmetry breaking are obtained. We show they evolve continuously into each other by tuning the second- and third-neighbor interactions. At last, we discuss the possible implication of our results on the nature of spin liquid in nearest neighbor XXZ kagome antiferromagnets, including the most studied nearest neighbor spin-$1/2$ kagome anti-ferromagnetic Heisenberg model