The Interspersed Spin Boson Lattice Model

TL;DR

This paper introduces a new lattice model combining spin and bosonic degrees of freedom, explores its phase diagram numerically, develops an improved analytic groundstate approximation, and proposes an experimental protocol for probing excitations, with potential circuit-QED implementation.

Contribution

It presents a novel interspersed spin-boson lattice model, combines numerical and analytic methods for its analysis, and proposes an experimental approach for realization and excitation detection.

Findings

Mapped the full phase diagram using Matrix-Product-State methods

Developed a variational ansatz for low boson frequencies

Proposed an experimental protocol for Fano scattering spectroscopy

Abstract

We describe a family of lattice models that support a new class of quantum magnetism characterized by correlated spin and bosonic ordering [Phys. Rev. Lett. 112, 180405 (2014)]. We explore the full phase diagram of the model using Matrix-Product-State methods. Guided by these numerical results, we describe a modified variational ansatz to improve our analytic description of the groundstate at low boson frequencies. Additionally, we introduce an experimental protocol capable of inferring the low-energy excitations of the system by means of Fano scattering spectroscopy. Finally, we discuss the implementation and characterization of this model with current circuit-QED technology.