We investigate the ground state properties of one-dimensional hard-core bosons interacting via a variable long-range potential using the density matrix renormalization group. We show that restoring energy extensivity in the system, which is done by rescaling the interaction potential with a suitable size-dependent factor known as Kac’s prescription, has a profound influence on the low-energy properties in the thermodynamic limit. While an insulating phase is found in the absence of Kac’s rescaling, the latter leads to a new metallic phase that does not fall into the conventional Luttinger liquid paradigm. We discuss a scheme for the observation of this new phase using cavity-mediated long-range interactions with cold atoms. Our findings raise fundamental questions on how to study the thermodynamics of long-range interacting quantum systems.
T. Botzung, D. Hagenmüller, G. Masella, J. Dubail, N. Defenu, A. Trombettoni, and G. Pupillo, “Effects of energy extensivity on the quantum phases of long-range interacting systems”, Phys. Rev. B 103, 155139 (2021).
Related to Project C02