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arXiv · 1803.01461

Fermi surfaces in Kondo insulators

Hsu Liu·Mate Hartstein·Gregory J. Wallace·Alexander J. Davies·Monica Ciomaga Hatnean·Michelle D. Johannes·Natalya Shitsevalova·Geetha Balakrishnan·Suchitra E. Sebastian
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Abstract

We report magnetic quantum oscillations measured using torque magnetisation in the Kondo insulator YbB$_{12}$ and discuss the potential origin of the underlying Fermi surface. Observed quantum oscillations as well as complementary quantities such as a finite linear specific heat capacity in YbB$_{12}$ exhibit similarities with the Kondo insulator SmB$_6$, yet also crucial differences. Small heavy Fermi sections are observed in YbB$_{12}$ with similarities to the neighbouring heavy fermion semimetallic Fermi surface, in contrast to large light Fermi surface sections in SmB$_6$ which are more similar to the conduction electron Fermi surface. A rich spectrum of theoretical models is suggested to explain the origin across different Kondo insulating families of a bulk Fermi surface potentially from novel itinerant quasiparticles that couple to magnetic fields, yet do not couple to weak DC electric fields.

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Hsu Liu, Mate Hartstein, Gregory J. Wallace, Alexander J. Davies, Monica Ciomaga Hatnean, Michelle D. Johannes, Natalya Shitsevalova, Geetha Balakrishnan, Suchitra E. Sebastian. 2018-03-05. Fermi surfaces in Kondo insulators. https://doi.org/10.1088/1361-648x/aaa522

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