Itinerant Magnetism in a Dipolar Lattice Gas II - Youcef Baamara
ORAL
Abstract
Itinerant magnetism appears when particles can move while interacting, making it a rich and challenging many-body problem that is closely connected to superconductivity, quantum magnetism, and superfluidity. Magnetic dipolar gases in optical lattices provide an ideal platform to explore this physics, because tunneling, contact interactions, and long-range anisotropic dipolar interactions all play important roles.
In this work, we study how the transverse magnetization evolves as the system moves from a regime where atoms can move freely to one dominated by interactions. By tuning the depth and geometry of a 3D optical lattice, we explore the crossover from the superfluid phase to the Mott insulator. In the superfluid regime, the gas maintains a ferromagnetic character, but deeper lattices gradually suppress spin transport, leading to a dynamical instability near the transition. In the insulating regime, the dynamics can be described using effective spin models where the superexchange term combines both onsite dipolar interactions and contact interactions, together with additional long-range dipolar couplings. To clarify the underlying physics, we build a simple spin-1 model that captures the essential behavior, along with a full treatment of the spin-3 dynamics.
Our analysis provides new tools and insights into itinerant dipolar magnetism in optical lattices.
In this work, we study how the transverse magnetization evolves as the system moves from a regime where atoms can move freely to one dominated by interactions. By tuning the depth and geometry of a 3D optical lattice, we explore the crossover from the superfluid phase to the Mott insulator. In the superfluid regime, the gas maintains a ferromagnetic character, but deeper lattices gradually suppress spin transport, leading to a dynamical instability near the transition. In the insulating regime, the dynamics can be described using effective spin models where the superexchange term combines both onsite dipolar interactions and contact interactions, together with additional long-range dipolar couplings. To clarify the underlying physics, we build a simple spin-1 model that captures the essential behavior, along with a full treatment of the spin-3 dynamics.
Our analysis provides new tools and insights into itinerant dipolar magnetism in optical lattices.
*This work is supported by the AFOSR FA9550-24-1-0179, the Vannevar Bush Faculty Fellowship, the NSF JILA-PFC PHY-2317149, OMA-2016244 (QLCI), the U.S. Department of Energy, Office of Science, and National Quantum Information Science Research Centers, Quantum Systems Accelerator.
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Publication: Probing Coherences and Itinerant Magnetism in a Dipolar Lattice Gas, Thomas Lauprêtre, Jose Daniel Bernal, Youcef Baamara, Ana Maria Rey, Laurent Vernac, Bruno Laburthe-Tolra.
Using Dynamical Decoupling to investigate Magnetism of large spin atoms, Thomas Lauprêtre, Jose Daniel Bernal, Youcef Baamara, Ana Maria Rey, Laurent Vernac, Bruno Laburthe-Tolra.
Presenters
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Youcef BAAMARA
- JILA