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Competing density-wave orders in a one-dimensional hard-boson model

Paul Fendley·K. Sengupta·Subir Sachdev
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Abstract

We describe the zero-temperature phase diagram of a model of bosons, occupying sites of a linear chain, which obey a hard-exclusion constraint: any two nearest-neighbor sites may have at most one boson. A special case of our model was recently proposed as a description of a ``tilted'' Mott insulator of atoms trapped in an optical lattice. Our quantum Hamiltonian is shown to generate the transfer matrix of Baxter's hard-square model. Aided by exact solutions of a number of special cases, and by numerical studies, we obtain a phase diagram containing states with long-range density-wave order with period 2 and period 3, and also a floating incommensurate phase. Critical theories for the various quantum phase transitions are presented. As a byproduct, we show how to compute the Luttinger parameter in integrable theories with hard-exclusion constraints.

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Paul Fendley, K. Sengupta, Subir Sachdev. 2003-09-21. Competing density-wave orders in a one-dimensional hard-boson model. https://doi.org/10.1103/physrevb.69.075106

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