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arXiv · 1604.01228

Ising tricriticality in the extended Hubbard model with bond dimerization

Satoshi Ejima·Fabian H. L. Essler·Florian Lange·Holger Fehske
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Abstract

We explore the quantum phase transition between Peierls and charge-density-wave insulating states in the one-dimensional, half-filled, extended Hubbard model with explicit bond dimerization. We show that the critical line of the continuous Ising transition terminates at a tricritical point, belonging to the universality class of the tricritical Ising model with central charge $c=7/10$. Above this point, the quantum phase transition becomes first order. Employing a numerical matrix-product-state based (infinite) density-matrix renormalization group method we determine the ground-state phase diagram, the spin and two-particle charge excitations gaps, and the entanglement properties of the model with high precision. Performing a bosonization analysis we can derive a field description of the transition region in terms of a triple sine-Gordon model. This allows us to derive field theory predictions for the power-law (exponential) decay of the density-density (spin-spin) and bond-order-wave correlation functions, which are found to be in excellent agreement with our numerical results.

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Satoshi Ejima, Fabian H. L. Essler, Florian Lange, Holger Fehske. 2016-06-12. Ising tricriticality in the extended Hubbard model with bond dimerization. https://doi.org/10.1103/physrevb.93.235118

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