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arXiv · 2204.00029

Spin chain on a metallic surface: Dissipation-induced order vs. Kondo entanglement

Bimla Danu·Matthias Vojta·Tarun Grover·Fakher F. Assaad
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Abstract

We explore the physics of a spin-1/2 Heisenberg chain with Kondo interaction, $J_k$, to a two-dimensional electron gas. At weak $J_k$ the problem maps onto a Heisenberg chain locally coupled to a dissipative Ohmic bath. At the decoupled fixed point, the dissipation is a marginally relevant perturbation and drives long-range antiferromagnetic order along the chain. In the dynamical spin structure factor we observe a quadratic low-energy dispersion akin to Landau-damped Goldstone modes. At large $J_k$ Kondo screening dominates, and the spin correlations of the chain inherit the power law of the host metal, akin to a paramagnetic heavy Fermi liquid. In both phases we observe heavy bands near the Fermi energy in the composite-fermion spectral function. Our results, obtained from auxiliary-field quantum Monte Carlo simulations, provide a unique negative-sign-free realization of a quantum transition between an antiferromagnetic metal and a heavy-fermion metal. We discuss the relevance of our results in the context of scanning tunneling spectroscopy experiments of magnetic adatom chains on metallic surfaces.

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Bimla Danu, Matthias Vojta, Tarun Grover, Fakher F. Assaad. 2022-03-31. Spin chain on a metallic surface: Dissipation-induced order vs. Kondo entanglement. https://doi.org/10.1103/physrevb.106.l161103

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