Spin liquid fingerprints in the thermal transport of a Kitaev-Heisenberg ladder
Abstract
We identify fingerprints of a proximate quantum spin liquid (QSL), observable by finite-temperature dynamical thermal transport within a minimal version of the idealized Kitaev model on a two-leg ladder if subjected to inevitably present Heisenberg couplings. Using exact diagonalization and quantum typicality, we uncover (i) an insulator-conductor crossover induced by recombination of fractionalized excitations at small Heisenberg couplings, (ii) low- and high-energy signatures of fractionalized excitations, which survive far off the pure QSL point, and (iii) a nonmonotonous current lifetime versus Heisenberg couplings. Guided by perturbation theory, we find (iv) a Kitaev-exchange-induced "one-magnon" contribution to the dynamical heat transport in the strong Heisenberg rung limit.
- Publication:
-
Physical Review B
- Pub Date:
- May 2019
- DOI:
- 10.1103/PhysRevB.99.205129
- arXiv:
- arXiv:1806.02344
- Bibcode:
- 2019PhRvB..99t5129M
- Keywords:
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- Condensed Matter - Strongly Correlated Electrons
- E-Print:
- 6 pages, 4 figures. See also ancillary files