Reduction of the low-temperature bulk gap in samarium hexaboride under high magnetic fields

Abstract

SmB${}_6$ exhibits a small (15-20 meV) bandgap at low temperatures due to hybridized $d$ and $f$ electrons, a tiny (3 meV) transport activation energy $(E_A)$ above 4 K, and surface states accessible to transport below 2 K. We study its magnetoresistance in 60-T pulsed fields between 1.5 K and 4 K. The response of the nearly $T$-independent surface states (which show no Shubnikov-de Haas oscillations) is distinct from that of the activated bulk. $E_A$ shrinks by 50% under fields up to 60 T. Data up to 93 T suggest that this trend continues beyond 100 T, in contrast with previous explanations. It rules out emerging theories to explain observed exotic magnetic quantum oscillations.

arXiv comment12 pages, 3 figures

References in corpus (24)

• Topological Kondo Insulators
• Surface electronic structure of the topological Kondo insulator candidate correlated electron system SmB6
• Low-temperature surface conduction in the Kondo insulator SmB${}_6$
• Correlated Topological Insulators with Mixed Valence
• Quantum oscillations in Kondo Insulator SmB${}_6$
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• Tuning bulk and surface conduction in topological Kondo insulator SmB6
• Quantum oscillations without a Fermi surface and the anomalous de Haas-van Alphen effect
• Quantum oscillation in narrow-gap topological insulators
• Kondo Breakdown and Quantum Oscillations in SmB${}_6$
• Momentum-Dependent Hybridization Gap and dispersive in-gap state of The Kondo Semiconductor SmB6
• One-dimensional edge state transport in a topological Kondo insulator
• Weak Antilocalization and Linear Magnetoresistance in The Surface State of SmB6
• The energy gap of intermediate-valent SmB6 studied by point-contact spectroscopy
• Chemical potential asymmetry and quantum oscillations in insulators
• Hysteretic Magnetotransport in SmB6 at Low Magnetic Fields
• Magnetotransport Measurements of the Surface States of Samarium Hexaboride using Corbino Structures
• Fractionalized Fermi liquid on the surface of a topological Kondo insulator
• Understanding low-temperature bulk transport in samarium hexaboride without relying on in-gap bulk states

Cited by in corpus (6)

• Observation of perfect Andreev reflection due to Klein paradox in a topological superconducting state
• Fermi surfaces in Kondo insulators
• Intrinsic bulk quantum oscillations in a bulk unconventional insulator SmB${}_6$
• Definitive Surface Magnetotransport Study of SmB${}_6$
• Magnetoquantum Oscillations in the Specific Heat of a Topological Kondo Insulator
• Cyclotron resonance in Kondo insulator