Dynamical signatures of thermal spin-charge deconfinement in the doped Ising model

Abstract

The mechanism underlying charge transport in strongly correlated quantum systems, such as doped antiferromagnetic Mott insulators, remains poorly understood. Here we study the expansion dynamics of an initially localized hole inside a two-dimensional (2D) Ising antiferromagnet at variable temperature. Using a combination of classical Monte Carlo and a truncated basis method, we reveal two dynamically distinct regimes: A spin-charge confined region below a critical temperature $T^{\ast }$, characterized by slow spreading, and a spin-charge deconfined region above $T^{\ast }$, characterized by an unbounded diffusive expansion. The deconfinement temperature $T^{\ast }\approx 0.65J_z$ we find is around the Néel temperature $T_{\mathrm{N}}=0.567J_z$ of the Ising background in 2D, but we expect $T^{\ast }<T_{\mathrm{N}}$ in higher dimensions. In both regimes we find that the mobile hole does not thermalize with the Ising spin background on the considered time scales, indicating weak effective coupling of spin- and charge degrees of freedom. Our results can be qualitatively understood by an effective parton model, and can be tested experimentally in state-of-the-art quantum gas microscopes.

10 pages, 8 figures

References in corpus (9)

• Time-resolved Observation and Control of Superexchange Interactions with Ultracold Atoms in Optical Lattices
• Coherent many-body spin dynamics in a long-range interacting Ising chain
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• Exploration of doped quantum magnets with ultracold atoms
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• Microscopic spinon-chargon theory of magnetic polarons in the t-J model
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• Spatial structure of magnetic polarons in strongly interacting antiferromagnets

Cited by in corpus (9)

• Strong pairing in mixed dimensional bilayer antiferromagnetic Mott insulators
• Realistic scheme for quantum simulation of ${\mathbb{Z}}_2$ lattice gauge theories with dynamical matter in $(2+1)$D
• Photo-induced nonequilibrium states in Mott insulators
• Finite-Temperature Hole-Magnon Dynamics in an Antiferromagnet
• Percolation as a confinement order parameter in ${\mathbb{Z}}_2$ lattice gauge theories
• Exact dynamics of two holes in two-leg antiferromagnetic ladders
• Thermally induced localization of dopants in a magnetic spin ladder
• Independent e- and m-anyon confinement in the parallel field toric code on non-square lattices
• Localized dopant motion across the 2D Ising phase transition