| The interplay of geometric randomness and strong quantum fluctuations is an exciting topic in quantum many-body physics, leading to novel quantum phases in strongly correlated electron systems. Recent investigations have focused on the case of homogeneous site and bond dilution in the quantum antiferromagnet on the square lattice, reporting a classical geometric percolation transition between magnetic order and disorder. In this seminar I discuss how non-homogeneous bond dilution can lead to percolative quantum phase transitions, which we have studied extensively by quantum Monte Carlo simulations. Quantum percolation this introduces a new class of two-dimensional quantum spin liquids, characterized by an infinite percolating network with vanishing antiferromagnetic order parameter. |
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