### Abstract

In the limit of weak exchange J at low hole concentration (formula presented) the ground state of the two-dimensional (formula presented) model is believed to be ferromagnetic. We study the leading instability of this Nagaoka state, which emerges with increasing J. Both exact diagonalization of small clusters, and a semiclassical analytical calculation of larger systems show that above a certain critical value of the exchange, (formula presented) Nagaoka’s state is unstable to phase separation. In a finite-size system a bubble of antiferromagnetic Mott insulator appears in the ground state above this threshold. The size of this bubble depends on (formula presented) and scales as a power of the system size N.

Original language | English (US) |
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Pages (from-to) | 1-7 |

Number of pages | 7 |

Journal | Physical Review B - Condensed Matter and Materials Physics |

Volume | 65 |

Issue number | 13 |

DOIs | |

State | Published - Jan 1 2002 |

### All Science Journal Classification (ASJC) codes

- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics

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## Cite this

*Physical Review B - Condensed Matter and Materials Physics*,

*65*(13), 1-7. https://doi.org/10.1103/PhysRevB.65.134437