Bose-Hubbard simulator with long-range hopping
Camille Lagoin, Corentin Morin, Kirk Baldwin, Loren Pfeiffer, Francois Dubin
TL;DR
The work demonstrates a Bose-Hubbard-like lattice of dipolar excitons in a GaAs bilayer with photon-mediated long-range hopping, described by $H = H_{eBH} + H_{LR}$ where $H_{LR} = \sum_{k,l}(J_{kl}-i\Gamma_{kl}/2)B^{\dagger}_k B_l$ and $J_{kl},\Gamma_{kl}$ encode coherent and dissipative long-range couplings. Time-resolved PL and Fourier-transform spectroscopy reveal algebraic decay of radiative dissipation and collective time coherence arising from long-range hopping, signaling photonic-channel mediated correlations across the lattice. Sub-radiant many-body states emerge, with long-range hopping together with nearest-neighbor repulsion stabilizing Mott-insulating (MI) and checkerboard (CB) phases; extended coherence appears only in these spatially ordered phases, suggesting condensation into a single sub-radiant mode in CB and MI. Nanoscopic exciton arrays therefore provide a platform to engineer strongly correlated lattice models with long-range correlations and potentially realize novel supersolid-like states at fractional fillings.
Abstract
Enriching condensed-matter systems with quantum optical phenomena currently drives intense research efforts, particularly to introduce collective quantum correlations. Here we access this paradigm, by confining dipolar excitons in a nanoscopic lattice where long-range hopping, and nearest-neighbour dipolar repulsions, dress the Bose-Hubbard Hamiltonian. Long-range hopping is evidenced by the spontaneous buildup of many-body sub-radiance, signalled by an algebraic slowdown of excitons radiative dissipation. In addition, we observe a threshold increase of temporal coherence for dipolar quantum solids only. It suggests that excitons condense in a single sub-radiant state for Mott-like phases. These combine then spatial order and collectively extended coherence, in a single degree of freedom. Our study unveils that nanoscopic exciton arrays provide a unique platform to design new frontiers of strongly-correlated lattice models with long-range correlations.