Entanglement entropy of disordered quantum wire junctions. (21st December 2018)

• Record Type: Journal Article
• Authors: Juhász, Róbert; Oberreuter, Johannes M; Zimborás, Zoltán
• Is Part Of: Journal of statistical mechanics. (2018:Dec.)
• Publication Date: 2018-12-21
• Subjects: 2; Statistical mechanics -- Periodicals; Mechanics -- Statistical methods -- Periodicals; 530.1305
• DOI: 10.1088/1742-5468/aaeda2
• Languages: English
• ISSNs: 1742-5468

Abstract

Abstract: We consider different disordered lattice models composed of M linear chains glued together in a star-like manner, and study the scaling of the entanglement between one arm and the rest of the system using a numerical strong-disorder renormalization group method. For all studied models, the random transverse-field Ising model (RTIM), the random XX spin model, and the free-fermion model with random nearest-neighbor hopping terms, the average entanglement entropy is found to increase with the length L of the arms according to the form . For the RTIM and the XX model, the effective central charge is universal with respect to the details of junction, and only depends on the number M of arms. Interestingly, for the RTIM, decreases with M, whereas for the XX model it increases. For the free-fermion model, depends also on the details of the junction, which is related to the sublattice symmetry of the model. In this case, both increasing and decreasing tendency with M can be realized with appropriate junction geometries.