Chern Gia-Wei, Maiti Saurabh, Fernandes Rafael M, Wölfle Peter
Theoretical Division, T-4 and CNLS, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA and Department of Physics, University of Wisconsin, Madison, Wisconsin 53706, USA.
Department of Physics, University of Wisconsin, Madison, Wisconsin 53706, USA.
Phys Rev Lett. 2013 Apr 5;110(14):146602. doi: 10.1103/PhysRevLett.110.146602. Epub 2013 Apr 2.
We investigate the transport properties of itinerant electrons interacting with a background of localized spins in a correlated paramagnetic phase of the pyrochlore lattice. We find a residual resistivity at zero temperature due to the scattering of electrons by the static dipolar spin-spin correlation that characterizes the metallic Coulomb phase. As temperature increases, thermally excited topological defects, also known as magnetic monopoles, reduce the spin correlation, hence suppressing electron scattering. Combined with the usual scattering processes in metals at higher temperatures, this mechanism yields a nonmonotonic resistivity, displaying a minimum at temperature scales associated with the magnetic monopole excitation energy. Our calculations agree quantitatively with resistivity measurements in Nd(2)Ir(2)O(7) and Pr(2)Ir(2)O(7), shedding light on the origin of the resistivity minimum observed in metallic spin-ice compounds.
我们研究了在焦绿石晶格的相关顺磁相中，巡游电子与局域自旋背景相互作用时的输运性质。我们发现，由于表征金属库仑相的静态偶极自旋 - 自旋关联对电子的散射作用，在零温度下存在残余电阻率。随着温度升高，热激发的拓扑缺陷（也称为磁单极子）会降低自旋关联，从而抑制电子散射。结合金属在较高温度下通常的散射过程，这种机制产生了非单调的电阻率，在与磁单极子激发能相关的温度尺度上呈现出最小值。我们的计算结果与在Nd(2)Ir(2)O(7)和Pr(2)Ir(2)O(7)中的电阻率测量结果在定量上相符，揭示了在金属自旋冰化合物中观察到的电阻率最小值的起源。
