Frustrated Quantum Magnetism on Complex Networks: What Sets the Total Spin

Preethi Gopalakrishnan; Shovan Dutta

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arXiv · 2403.09116

Frustrated Quantum Magnetism on Complex Networks: What Sets the Total Spin

Preethi Gopalakrishnan·Shovan Dutta

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Abstract

Consider equal antiferromagnetic Heisenberg interactions between qubits forming a complex, nonbipartite network. We ask the question: How does the network topology determine the net magnetization of the ground state and to what extent is it tunable? By examining over 75000 networks of different families with tunable structural properties, we demonstrate that (i) heterogeneity in the number of neighbors is essential for a nonzero total spin, and (ii) apart from the number of neighbors, the key determinant is the presence of (disassortative) hubs, as opposed to the frustration level. In fact, one can vary the magnetization throughout its range by embedding such hubs. We also discuss simple, exactly solvable networks where such tunability leads to both abrupt and continuous transitions, with quantum effects giving rise to a diverging susceptibility. Our findings can be realized on emerging platforms and pose a number of fundamental questions, strongly motivating wider exploration of quantum many-body phenomena on complex networks.

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cond-mat.dis-nn cond-mat.quant-gas cond-mat.stat-mech cond-mat.str-el

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BibTeX RIS

Preethi Gopalakrishnan, Shovan Dutta. 2024-03-14. Frustrated Quantum Magnetism on Complex Networks: What Sets the Total Spin. https://arxiv.org/abs/2403.09116

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