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arXiv · 1102.3606

Ferromagnetic instability and finite-temperature properties of two-dimensional electron systems with van Hove singularities

A. A. Katanin·H. Yamase·V. Yu. Irkhin
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Abstract

We study a ferromagnetic tendency in the two-dimensional Hubbard model near van Hove filling by using a functional renormalization-group method. We compute temperature dependences of magnetic susceptibilities including incommensurate magnetism. The ferromagnetic tendency is found to occur in a dome-shaped region around van Hove filling with an asymmetric property: incommensurate magnetism is favored near the edge of the dome above van Hove filling whereas a first-order-like transition to the ferromagnetic ground state is expected below van Hove filling. The dome-shaped phase diagram is well captured in the Stoner theory by invoking a smaller Coulomb interaction. Triplet p-wave superconductivity tends to develop at low temperatures inside the dome and extends more than the ferromagnetic region above van Hove filling.

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A. A. Katanin, H. Yamase, V. Yu. Irkhin. 2011-02-17. Ferromagnetic instability and finite-temperature properties of two-dimensional electron systems with van Hove singularities. https://doi.org/10.1143/jpsj.80.063702

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