Quantum half-orphans in kagome antiferromagnets

摘要: We numerically study the effects of non-magnetic impurities (vacancies) in spin-$S$ Heisenberg antiferromagnet on kagom\'e lattice. For a range low but nonzero temperatures, and spin values that extend down to $S=2$, we find magnetization response an external magnetic field is consistent with emergent "half-orphan" degrees freedom are expected dominate corresponding classical magnet similar temperature whenever there two vacancies same triangle. Specifically, for all have considered (from $S=1/2$ $S=4$), large enhancement local susceptibility lone such triangle vacancies; presence uniform $h$, this lone-spin behaves effectively as almost free $S$ effective $h/2$. Quite remarkably, zero limit, ground state half-orphan has non-zero total value $S_{GS}$ shows trend $S/2$ when $S\ge 2$. These qualitative aspects differ strikingly from more conventional diluted samples without freedom. discuss how these findings could be checked experimentally.