Experimental Realization of a Quantum Integer-Spin Chain with Controllable Interactions

TL;DR

This paper reports the experimental realization of a controllable quantum spin-1 chain using trapped ions, enabling the study of topological phases and symmetry-protected order in a highly tunable system.

Contribution

It introduces a novel experimental platform for simulating interacting spin-1 particles with controllable long-range couplings and demonstrates the creation of topologically nontrivial ground states.

Findings

Successfully entangled qutrits with 86% fidelity

Produced ground states of the XY model via adiabatic ramping

Observed symmetry-breaking in topological ground states

Abstract

The physics of interacting integer-spin chains has been a topic of intense theoretical interest, particularly in the context of symmetry-protected topological phases. However, there has not been a controllable model system to study this physics experimentally. We demonstrate how spin-dependent forces on trapped ions can be used to engineer an effective system of interacting spin-1 particles. Our system evolves coherently under an applied spin-1 XY Hamiltonian with tunable, long-range couplings, and all three quantum levels at each site participate in the dynamics. We observe the time evolution of the system and verify its coherence by entangling a pair of effective three-level particles (`qutrits') with 86% fidelity. By adiabatically ramping a global field, we produce ground states of the XY model, and we demonstrate an instance where the ground state cannot be created without breaking the same symmetries that protect the topological Haldane phase. This experimental platform enables future studies of symmetry-protected order in spin-1 systems and their use in quantum applications.