Quantum Simulation of Antiferromagnetic Spin Chains in an Optical Lattice
arXiv:1103.1372 · doi:10.1038/nature09994
Abstract
Understanding exotic forms of magnetism in quantum mechanical systems is a central goal of modern condensed matter physics, with implications from high temperature superconductors to spintronic devices. Simulating magnetic materials in the vicinity of a quantum phase transition is computationally intractable on classical computers due to the extreme complexity arising from quantum entanglement between the constituent magnetic spins. Here we employ a degenerate Bose gas confined in an optical lattice to simulate a chain of interacting quantum Ising spins as they undergo a phase transition. Strong spin interactions are achieved through a site-occupation to pseudo-spin mapping. As we vary an applied field, quantum fluctuations drive a phase transition from a paramagnetic phase into an antiferromagnetic phase. In the paramagnetic phase the interaction between the spins is overwhelmed by the applied field which aligns the spins. In the antiferromagnetic phase the interaction dominates and produces staggered magnetic ordering. Magnetic domain formation is observed through both in-situ site-resolved imaging and noise correlation measurements. By demonstrating a route to quantum magnetism in an optical lattice, this work should facilitate further investigations of magnetic models using ultracold atoms, improving our understanding of real magnetic materials.
12 pages, 9 figures
References in corpus (19)
- Many-Body Physics with Ultracold Gases
- Ultracold atomic gases in optical lattices: mimicking condensed matter physics and beyond
- A High Phase-Space-Density Gas of Polar Molecules
- Single-Atom Resolved Fluorescence Imaging of an Atomic Mott Insulator
- Single-Spin Addressing in an Atomic Mott Insulator
- Time-resolved Observation and Control of Superexchange Interactions with Ultracold Atoms in Optical Lattices
- Spatial quantum noise interferometry in expanding ultracold atom clouds
- Strongly correlated 2D quantum phases with cold polar molecules: controlling the shape of the interaction potential
- Quantum magnetism and criticality
- Strong and weak thermalization of infinite non-integrable quantum systems
- Itinerant Ferromagnetism in a Fermi Gas of Ultracold Atoms
- Observation of scale invariance and universality in two-dimensional Bose gases
- Quantum Magnets under Pressure: Controlling Elementary Excitations in TlCuCl3
- Implementation of Spin Hamiltonians in Optical Lattices
- Mott insulators in strong electric fields
- Cooling in strongly correlated optical lattices: prospects and challenges
- Sublattice addressing and spin-dependent motion of atoms in a double-well lattice
- Exploring quantum criticality based on ultracold atoms in optical lattices
- Effective spin model for interband transport in a Wannier-Stark lattice system