How can an insulator without a Fermi surface show quantum oscillations? · revision history

Revision 2

Accepted · core change · record

Changes against revision 1:

Title
How can an insulator without a Fermi surface show quantum oscillations?
Plain
Quantum oscillations normally require a sharp boundary between filled and empty electron states, which an insulator lacks. Proposed explanations range from field effects on the insulating gap to new particles that carry no charge.
Precise · changed · core
Revision 1: Candidates are Landau quantization of hybridized bands with a small inverted gap, which gives magnetization oscillations at the frequency of the unhybridized Fermi surface (Knolle and Cooper 2015); emergent neutral fermions with a Fermi surface (spinons, composite excitons, Majorana Fermi sea); and in-gap impurity bands or metallic inclusions. An answer predicts the frequency, the amplitude temperature dependence including deviations from Lifshitz-Kosevich form, and which quantities oscillate (magnetization, resistivity, heat capacity, thermopower) in SmB6, YbB12 and monolayer WTe2.
Revision 2: Candidates are Landau quantization of hybridized bands with a small inverted gap, which gives magnetization oscillations at the frequency of the unhybridized Fermi surface (Knolle and Cooper 2015); emergent neutral fermions with a Fermi surface (spinons, composite excitons, Majorana Fermi sea); and in-gap impurity bands or metallic inclusions. An answer predicts the frequency, the amplitude temperature dependence including deviations from Lifshitz-Kosevich form, and which quantities oscillate (magnetization, resistivity, heat capacity, thermopower) in $\mathrm{SmB_6}$, $\mathrm{YbB_{12}}$ and monolayer $\mathrm{WTe_2}$.
Settled by · changed · core
Revision 1: Amplitude versus temperature and gap size in a tunable system (pressure-tuned YbB12, gate-tuned WTe2 or InAs/GaSb wells) where the candidate theories make distinct predictions.
Revision 2: Amplitude versus temperature and gap size in a tunable system (pressure-tuned $\mathrm{YbB_{12}}$, gate-tuned $\mathrm{WTe_2}$ or InAs/GaSb wells) where the candidate theories make distinct predictions.
Kind
phenomenon
Answer type
mechanism
References
(empty)
Literature status
open
Status note
(empty)
Posed since
2015

Decisions