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arXiv · 2509.17110

Efficient simulation of a pair of dissipative qubits antiferromagnetically coupled

Francesco G. Capone·Giulio De Filippis·Vittorio Cataudella·Antonio de Candia
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Abstract

We investigate the efficiency of different quantum Monte Carlo simulations of a pair of antiferromagnetically coupled qubits in an Ohmic dissipative environment. Using a Trotter-Suzuky decomposition and integrating out the degrees of freedom of the thermal bath, the model maps onto a frustrated long-range double-chain Ising lattice. We prove that: i) due to frustration, the conventional Swendsen-Wang approach to cluster dynamics turns out to suffer from a severe inefficiency, stemming from the mismatch between spin correlations and cluster connectivity; ii) the Kandel-Domany approach is extremely effective in the study of dissipative quantum qubits. We partition the double-chain into different types of plaquettes and minimize the weight of graphs containing antiferromagnetic bonds by using both analytic and numerical approaches. Monte Carlo simulation results show that ``long range'' plaquette decompositions are more efficient than the ``local'' ones, especially for high levels of dissipation.

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Francesco G. Capone, Giulio De Filippis, Vittorio Cataudella, Antonio de Candia. 2025-09-21. Efficient simulation of a pair of dissipative qubits antiferromagnetically coupled. https://doi.org/10.1103/rt88-kqh5

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