Repository logo
 

f-electron hybridised Fermi surface in magnetic field-induced metallic YbB12

Published version
Peer-reviewed

Change log

Abstract

The nature of the Fermi surface observed in the recently discovered family of unconventional insulators starting with SmB6 and subsequently YbB12 is a subject of intense inquiry. Here we shed light on this question by comparing quantum oscillations between the high magnetic field-induced metallic regime in YbB12 and the unconventional insulating regime. In the field-induced metallic regime beyond 47 T, we find prominent quantum oscillations in the contactless resistivity characterised by multiple frequencies up to at least 3000 T and heavy effective masses up to at least 17 me, characteristic of an f-electron hybridised metallic Fermi surface. The growth of quantum oscillation amplitude at low temperatures in electrical transport and magnetic torque in insulating YbB12 is closely similar to the Lifshitz-Kosevich low temperature growth of quantum oscillation amplitude in field-induced metallic YbB12, pointing to an origin of quantum oscillations in insulating YbB12 from in-gap neutral low energy excitations. The field-induced metallic regime of YbB12 is characterised by more Fermi surface sheets of heavy quasiparticle effective mass that emerge in addition to the heavy Fermi surface sheets yielding multiple quantum oscillation frequencies below 1000 T observed in both insulating and metallic regimes. We thus observe a heavy multi-component Fermi surface in which f-electron hybridisation persists from the unconventional insulating to the field-induced metallic regime of YbB12, which is in distinct contrast to the unhybridised conduction electron Fermi surface observed in the case of the unconventional insulator SmB6. Our findings require a different theoretical model of neutral in-gap low energy excitations in which the f-electron hybridisation is retained in the case of the unconventional insulator YbB12.

Description

Funder: EC | EU Framework Programme for Research and Innovation H2020 | H2020 Priority Excellent Science | H2020 European Research Council (H2020 Excellent Science - European Research Council); doi: https://doi.org/10.13039/100010663


Funder: Ministry of Education (Ministry of Education, Republic of China (Taiwan)); doi: https://doi.org/10.13039/100010002


Funder: RCUK | Engineering and Physical Sciences Research Council (EPSRC); doi: https://doi.org/10.13039/501100000266


Funder: RCUK | Economic and Social Research Council (ESRC); doi: https://doi.org/10.13039/501100000269


Funder: Deutsche Forschungsgemeinschaft (German Research Foundation); doi: https://doi.org/10.13039/501100001659


Funder: National Science Foundation (NSF); doi: https://doi.org/10.13039/100000001


Funder: United States Department of Defense | United States Navy | Office of Naval Research (ONR); doi: https://doi.org/10.13039/100000006

Keywords

cond-mat.str-el, cond-mat.str-el

Journal Title

npj Quantum Materials

Conference Name

Journal ISSN

2397-4648
2397-4648

Volume Title

7

Publisher

Springer Science and Business Media LLC
Sponsorship
European Research Council (337425)
Engineering and Physical Sciences Research Council (EP/M000524/1)
Engineering and Physical Sciences Research Council (EP/M506485/1)
Engineering and Physical Sciences Research Council (EP/P024947/1)
European Research Council (772891)
EPSRC (1805236)
EPSRC (2124504)
Engineering and Physical Sciences Research Council (EP/S019367/1)
Engineering and Physical Sciences Research Council (EP/R00661X/1)