Emergent devil's staircase without particle-hole symmetry in Rydberg quantum gases with competing attractive and repulsive interactions

Lan, Zhihao; Min�?, Ji?�; Levi, Emanuele; Li, Weibin; Lesanovsky, Igor

Abstract

The devil's staircase is a fractal structure that characterizes the ground state of one-dimensional classical lattice gases with long-range repulsive convex interactions. Its plateaus mark regions of stability for specific filling fractions which are controlled by a chemical potential. Typically such staircase has an explicit particle-hole symmetry, i.e., the staircase at more than half-filling can be trivially extracted from the one at less than half filling by exchanging the roles of holes and particles. Here we introduce a quantum spin chain with competing short-range attractive and long-range repulsive interactions, i.e. a non-convex potential. In the classical limit the ground state features generalized Wigner crystals that --- depending on the filling fraction --- are either composed of dimer particles or dimer holes which results in an emergent complete devil's staircase without explicit particle-hole symmetry of the underlying microscopic model. In our system the particle-hole symmetry is lifted due to the fact that the staircase is controlled through a two-body interaction rather than a one-body chemical potential. The introduction of quantum fluctuations through a transverse field melts the staircase and ultimately makes the system enter a paramagnetic phase. For intermediate transverse field strengths, however, we identify a region, where the density-density correlations suggest the emergence of quasi long-range order. We discuss how this physics can be explored with Rydberg-dressed atoms held in a lattice.

Citation

Lan, Z., Minář, J., Levi, E., Li, W., & Lesanovsky, I. (2015). Emergent devil's staircase without particle-hole symmetry in Rydberg quantum gases with competing attractive and repulsive interactions. Physical Review Letters, 115, Article 203001. https://doi.org/10.1103/PhysRevLett.115.203001

• Journal Article Type: Article
• Publication Date: Nov 11, 2015
• Deposit Date: Dec 3, 2015
• Publicly Available Date: Dec 3, 2015
• Journal: Physical Review Letters
• Print ISSN: 0031-9007
• Electronic ISSN: 1079-7114
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 115
• Article Number: 203001
• DOI: https://doi.org/10.1103/PhysRevLett.115.203001
• Public URL: https://nottingham-repository.worktribe.com/output/767133
• Publisher URL: http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.115.203001