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TT: Fachverband Tiefe Temperaturen
TT 65: Quantum-Critical Phenomena II
TT 65.4: Talk
Wednesday, March 14, 2018, 15:45–16:00, HFT-FT 131
Tricriticality in the spin-1 XXZ chain with explicit bond dimerization — •Satoshi Ejima1, Tomoki Yamaguchi2, Florian Lange1, Yukinori Ohta2, and Holger Fehske1 — 1Institut für Physik, Ernst-Moritz-Arndt-Universität Greifswald, 17489 Greifswald, Germany — 2Department of Physics, Chiba University, Chiba 263-8522, Japan
Applying the matrix-product-state based density-matrix renormalization group technique to the spin-1 XXZ chain with bond dimerization, we explore the competition between two different symmetry-protected-topological phases, Peierls and Haldane states. The bond dimerization narrows the Haldane phase, and only dimerized and Néel state survive for large dimerization. The critical line between these two states exhibits the continuous Ising transition with central charge c=1/2, which terminates at a tricritical point, belonging to the universality class of the dilute Ising model with central charge c=7/10. Above this point, the quantum phase transition becomes first order. We provide compelling evidence for the (tricritical) Ising quantum phase transition, simulating corresponding critical exponents, β=1/8 (1/24) and ν=1 (5/9).