Thermodynamics of the Topological Kondo Model
arXiv:1412.5292 · doi:10.1016/j.nuclphysb.2015.04.016
Abstract
Using the thermodynamic Bethe ansatz, we investigate the topological Kondo model, which describes a set of one-dimensional external wires, pertinently coupled to a central region hosting a set of Majorana bound states. After a short review of the Bethe ansatz solution, we study the system at finite temperature and derive its free energy for arbitrary (even and odd) number of external wires. We then analyse the ground state energy as a function of the number of external wires and of their couplings to the Majorana bound states. Then, we compute, both for small and large temperatures, the entropy of the Majorana degrees of freedom localized within the central region and connected to the external wires. Our exact computation of the impurity entropy provides evidence of the importance of fermion parity symmetry in the realization of the topological Kondo model. Finally, we also obtain the low-temperature behaviour of the specific heat of the Majorana bound states, which provides a signature of the non-Fermi-liquid nature of the strongly coupled fixed point.
42 pages, 4 figures. v2: Comments about the role of the fermion parity added, appendix expanded
References in corpus (12)
- Non-Abelian Anyons and Topological Quantum Computation
- Dirac materials
- Matter-wave interferometry in a double well on an atom chip
- Observation of the two-channel Kondo effect
- Topological Kondo effect with Majorana fermions
- Dynamics of one-dimensional Bose liquids: Andreev-like reflection at Y-junctions and absence of the Aharonov-Bohm effect
- Quantum spins on star graphs and the Kondo model
- Bethe ansatz solution of the topological Kondo model
- Optically guided beam splitter for propagating matter waves
- Density matrix renormalization group algorithms for Y-junctions
- Regular networks of Luttinger liquids
- Stretching the electron as far as it will go