Regensburg 2019 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 21: Focus Session: Quantum Dynamics of Kinetically Constrained Many-Body Systems (joint session TT/DY)
TT 21.2: Hauptvortrag
Dienstag, 2. April 2019, 10:00–10:30, H2
DMRG investigation of constrained models: from quantum dimer and quantum loop ladders to hard-boson and Fibonacci anyon chains — •Natalia Chepiga1 and Frederic Mila2 — 1University of California, Irvine, USA — 2EPFL, Lausanne, Switzerland
Motivated by the presence of Ising transitions that take place entirely in the singlet sector of frustrated spin-1/2 ladders and spin-1 chains, we study two types of effective dimer models on ladders, a quantum dimer model and a quantum loop model. We further show that both models can be mapped rigorously onto a hard-boson model first studied by Fendley, Sengupta and Sachdev [Phys. Rev. B 69, 075106 (2004)]. Building on a density-matrix renormalization group algorithm that takes full advantage of the dimers constraints, we study systems with up to 9'000 sites and calculate the correlation length and the wave-vector of the incommensurate short-range correlations with unprecedented accuracy. We discuss the full phase diagram of these models, with special emphasis on the phase transitions. In particular, we provide strong numerical evidence that there is an intermediate floating phase far enough from the integrable Potts point, while in its vicinity, our numerical data are consistent with a unique transition in the Huse-Fisher chiral universality class. Moreover, using conformal field theory, we fully characterize the tricritical Ising point, with a complete analysis of the boundary-field correspondence including partially polarized edges.