In metals, orbital motions of conduction electrons on the Fermi surface are quantized in magnetic fields, which is manifested by quantum oscillations in electrical resistivity. This Landau quantization is generally absent in insulators. Here, we report a notable exception in an insulator—ytterbium dodecaboride (YbB_{12}). The resistivity of YbB_{12}, which is of a much larger magnitude than the resistivity in metals, exhibits distinct quantum oscillations. These unconventional oscillations arise from the insulating bulk, even though the temperature dependence of the oscillation amplitude follows the conventional Fermi liquid theory of metals with a large effective mass. Quantum oscillations in the magnetic torque are also observed, albeit with a lighter effective mass.
more » « less NSFPAR ID:
 10076792
 Publisher / Repository:
 American Association for the Advancement of Science (AAAS)
 Date Published:
 Journal Name:
 Science
 Volume:
 362
 Issue:
 6410
 ISSN:
 00368075
 Page Range / eLocation ID:
 65 to 69
 Format(s):
 Medium: X
 Sponsoring Org:
 National Science Foundation
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