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Spin-Charge Coupling in lightly doped Nd$_{2-x}$Ce$_{x}$CuO$_4$

Shiliang Li·Stephen D. Wilson·David Mandrus·Bairu Zhao·Y. Onose·Y. Tokura·Pengcheng Dai
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Abstract

We use neutron scattering to study the influence of a magnetic field on spin structures of Nd$_2$CuO$_4$. On cooling from room temperature, Nd$_2$CuO$_4$ goes through a series of antiferromagnetic (AF) phase transitions with different noncollinear spin structures. While a c-axis aligned magnetic field does not alter the basic zero-field noncollinear spin structures, a field parallel to the CuO$_2$ plane can transform the noncollinear structure to a collinear one ("spin-flop" transition), induce magnetic disorder along the c-axis, and cause hysteresis in the AF phase transitions. By comparing these results directly to the magnetoresistance (MR) measurements of Nd$_{1.975}$Ce$_{0.025}$CuO$_4$, which has essentially the same AF structures as Nd$_2$CuO$_4$, we find that a magnetic-field-induced spin-flop transition, AF phase hysteresis, and spin c-axis disorder all affect the transport properties of the material. Our results thus provide direct evidence for the existence of a strong spin-charge coupling in electron-doped copper oxides.

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Shiliang Li, Stephen D. Wilson, David Mandrus, Bairu Zhao, Y. Onose, Y. Tokura, Pengcheng Dai. 2004-11-27. Spin-Charge Coupling in lightly doped Nd$_{2-x}$Ce$_{x}$CuO$_4$. https://doi.org/10.1103/physrevb.71.054505

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