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arXiv:cond-mat/0106616

Electronic Structure near Impurities in the Chains of YBa$_2$Cu$_3$O$_{6+x}$

Dirk K. Morr, Alexander V. Balatsky

Published Jun 28, 2001• 0 citations
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Abstract

We study the electronic structure near impurities in the one-dimensional chains of YBa$_2$Cu$_3$O$_{6+x}$. Assuming chain superconductivity below $T_c$ due to a proximity coupling, we show that only a magnetic impurity induces resonance states in the local density of states. Its spatial structure reflects the particle-hole nature of chain superconductivity and thus distinguishes it from other broken symmetry phases. For a sufficiently large scattering strength, or due to interference effects arising from a second impurity, the chains undergo a quantum phase transition to a polarized state.

DOI
10.48550/arxiv.cond-mat/0106616

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We study the electronic structure near impurities in the one-dimensional chains of YBa2_22​Cu3_33​O6+x_{6+x}6+x​. Assuming chain superconductivity below TcT_cTc​ due to a proximity coupling, we show that only a magnetic impurity induces resonance states in the local density of states. Its spatial structure reflects the particle-hole nature of chain superconductivity and thus distinguishes it from other broken symmetry phases. For a sufficiently large scattering strength, or due to interference effects arising from a second impurity, the chains undergo a quantum phase transition to a polarized state.
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Scattering by a single impurity introduced in a strongly correlated electronic system is studied by exact diagonalization of small clusters. It is shown that an inert site which is spinless and unable to accommodate holes can give rise to strong resonant scattering. A calculation of the local density of states reveals that, for increasing antiferromagnetic exchange coupling, d,- s,- and p-wave symmetry bound states in which a mobile hole is trapped by the impurity potential induced by a local distortion of the antiferromagnetic background successively pull out from the continuum.