Quantum phase diagram for two species hardcore bosons in one-dimensional optical lattices with the resonantly driven Rabi frequency

TL;DR

This paper explores the quantum phase diagram of two-species hardcore bosons in a one-dimensional optical lattice with a resonantly driven Rabi frequency, revealing complex phase transitions and symmetry-breaking phenomena.

Contribution

It introduces a novel effective Hamiltonian for driven two-species hardcore bosons and analyzes the resulting quantum phases and transitions at integer filling.

Findings

Identification of a double-degenerate dimerized state at dominant J1

Discovery of three BKT transition lines and a tricritical BKT point

Exact determination of transition lines using level spectroscopy

Abstract

We propose an experimental realization of the time-periodically modulated Rabi frequency and suggest density-dependent hoppings of two species hardcore bosons in a one-dimensional optical lattice. Distinct from the previous work [Phys. Rev. Research {\bf 2}, 013275 (2020)], we study effects in the first resonance region. In the effective Hamiltonian, the intra-species hopping occurs only if the density discrepancy of the other species on these sites is zero, while the inter-species one is allowed once the relevant density discrepancy becomes nonzero. At integer-$1$ filling, the quantum phase diagram of the effective Hamiltonian is determined by the perturbation analysis together with numerical calculations. We find that in the limit of dominant $J_{1}$, the system becomes a double-degenerate dimerized state, with spontaneously breaking the translation symmetry. The interplay of $J_{0}$, $J_{1}$ and the fixed ${\bar U}=1$ leads to three BKT transition lines and a tricritical BKT point. Exact transition lines are obtained by the level spectroscopic technique. Besides, general physical properties, including the charge gap, neutral gap, superfluid density and dimerization strength, are investigated as well.