Condensation versus Long-range Interaction: Competing Quantum Phases in Bosonic Optical Lattice Systems at Near-resonant Rydberg Dressing

TL;DR

This paper investigates the complex quantum phases in Rydberg-dressed bosonic optical lattice systems, revealing a rich phase diagram with crystalline and supersolid phases due to long-range interactions and finite hopping.

Contribution

It provides the first detailed phase diagram near resonance including long-range interactions using real-space bosonic dynamical mean-field theory.

Findings

Identification of a devil's staircase of incommensurate density wave phases

Discovery of supersolid phases emerging from crystalline order

Extension of crystalline phases into the supersolid regime

Abstract

Recent experiments have shown that (quasi-)crystalline phases of Rydberg-dressed quantum many-body systems in optical lattices (OL) are within reach. Rydberg systems naturally possess strong long-range interactions due to the large polarizability of Rydberg atoms. Thus a wide range of quantum phases have been predicted, such as a devil's staircase of lattice incommensurate density wave phases as well as more exotic lattice supersolid order for bosonic systems, as considered in our work. Guided by results in the "frozen" gas limit, we study the ground state phase diagram at finite hopping amplitudes and in the vicinity of resonant Rydberg driving, while fully including the long-range tail of the van der Waals interaction. Simulations within real-space bosonic dynamical mean-field theory (RB-DMFT) yield an extension of the devil's staircase into the supersolid regime where the competition of condensation and interaction leads to a sequence of crystalline phases.