Heat transport in the Kondo insulator SmB<sub>6</sub>
COFFEE_KLATCH · Invited
Abstract
We have measured the thermal conductivity of the Kondo insulator SmB6 at temperatures down to 70 mK, in a magnetic field up to 15 T. Several samples grown by floating-zone method were investigated [1] as well as flux grown samples. We observe a large enhancement of thermal conductivity with field, but no residual linear term at T = 0 in any field. We discuss two possible mechanisms for the field dependence:
1) heat transport by phonons scattered by low-energy magnetic excitations;
2) heat transport by magnetic excitations.
Furthermore, the field dependence is anisotropic depending on whether the magnetic field is applied parallel or perpendicular to the heat current. This anisotropy varies significantly from sample to sample, indicating that magnetic impurities may play an important role in the heat transport of SmB6.
We compare our results to a recently published study [2] and discuss how to reconcile current discrepancies in experimental observations on SmB6.
[1] M-E. Boulanger et al., arxiv: 1709.10456
[2] M. Hartstein et al., Nat. Phys. (2017)
1) heat transport by phonons scattered by low-energy magnetic excitations;
2) heat transport by magnetic excitations.
Furthermore, the field dependence is anisotropic depending on whether the magnetic field is applied parallel or perpendicular to the heat current. This anisotropy varies significantly from sample to sample, indicating that magnetic impurities may play an important role in the heat transport of SmB6.
We compare our results to a recently published study [2] and discuss how to reconcile current discrepancies in experimental observations on SmB6.
[1] M-E. Boulanger et al., arxiv: 1709.10456
[2] M. Hartstein et al., Nat. Phys. (2017)
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Presenters
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Francis Laliberte
- Institut quantique, University of Sherbrooke
- Univ of Sherbrooke
- Université de Sherbrooke
- University of Sherbrooke
- Institut Quantique, Universite de Sherbrooke