On the sign structure of doped Mott insulators

K. Wu; Z. Y. Weng; J. Zaanen

doi:10.1103/physrevb.77.155102

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arXiv · 0802.0273

On the sign structure of doped Mott insulators

K. Wu·Z. Y. Weng·J. Zaanen

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Abstract

We demonstrate that the sign structure of the t-J model on a hypercubic lattice is entirely different from that of a Fermi gas, by inspecting the high temperature expansion of the partition function up to all orders, as well as the multi-hole propagator of the half-filled state and the perturbative expansion of the ground state energy. We show that while the fermion signs can be completely gauged away by a Marshall sign transformation at half-filling, the bulk of the signs can be also gauged away in a doped case, leaving behind a rarified "irreducible" sign structure that can be enumerated easily by counting exchanges of holes with themselves and spins on their real space paths. Such a sparse sign structure implies a mutual statistics for the quantum states of the doped Mott insulator.

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K. Wu, Z. Y. Weng, J. Zaanen. 2008-02-03. On the sign structure of doped Mott insulators. https://doi.org/10.1103/physrevb.77.155102

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