Altermagnetic pseudogap from $\frac{t}{U}$ expansion

Rohit Hegde

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arXiv · 2603.16311

Altermagnetic pseudogap from $\frac{t}{U}$ expansion

Rohit Hegde

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Abstract

Order parameter analysis of the t/U series reveals a uniform altermagnet endemic to the doped Mott insulator, driven by kinetic interactions, occupying a position between the antiferromagnet and hole-doped d-wave superconductor that is normally reserved for the pseudogap. The metastable boundary of the altermagnet punctures and divides the superconductor into underdoped and overdoped regions, reminiscent of the $T^\ast$ crossover or transition in the cuprates. Similarly, the $T_{pair}$ boundary of the superconductor divides the altermagnet, leading to a low temperature phase susceptible to Cooper fluctuations. The altermagnet is unstable to inhomegeneous spin and charge order of sites, bonds, and currents. Its leading instability is to the $\pi$-flux state, suggesting the possible emergence of spin-charge liquids and quantum ordered states from a physically realistic microscopic model.

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Rohit Hegde. 2026-03-17. Altermagnetic pseudogap from $\frac{t}{U}$ expansion. https://arxiv.org/abs/2603.16311

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