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Dynamics and Transport in Random Antiferromagnetic Spin Chains

Kedar Damle·Olexei Motrunich·David A. Huse
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Abstract

We present the first results on the low-frequency dynamical and transport properties of random antiferromagnetic spin chains at low temperature ($T$). We obtain the momentum and frequency dependent dynamic structure factor in the Random Singlet (RS) phases of both spin-1/2 and spin-1 chains, as well as in the Random Dimer phase of spin-1/2 chains. We also show that the RS phases are unusual `spin-metals' with divergent low-frequency conductivity at T=0, and follow the spin conductivity through `metal-insulator' transitions tuned by the strength of dimerization or Ising anisotropy in the spin-1/2 case, and by the strength of disorder in the spin-1 case.

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Kedar Damle, Olexei Motrunich, David A. Huse. 1999-11-11. Dynamics and Transport in Random Antiferromagnetic Spin Chains. https://doi.org/10.1103/physrevlett.84.3434

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