Persistence of correlation-driven surface states in SmB6 under pressure

Soonbeom Seo, Yongkang Luo, S. M. Thomas, Z. Fisk, O. Erten, P. S. Riseborough, F. Ronning, J. D. Thompson, P. F.S. Rosa

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


The proposed topological Kondo insulator SmB6 hosts a bulk Kondo hybridization gap that stems from strong electronic correlations and a metallic surface state whose effective mass remains disputed. Thermopower and scanning tunneling spectroscopy measurements argue for heavy surface states that also stem from strong correlations, whereas quantum oscillation and angle-resolved photoemission measurements reveal light effective masses that would be consistent with a Kondo breakdown scenario at the surface. Here we investigate the evolution of the surface state via electrical and thermoelectric transport measurements under hydrostatic pressure, a clean symmetry-preserving tuning parameter that suppresses the Kondo gap and increases the valence of Sm from ∼2.6+ towards a 3+ magnetic metallic state. Electrical resistivity measurements reveal that the surface carrier density increases with increasing pressure, whereas thermopower measurements show an unchanged Fermi energy under pressure. As a result, the effective mass of the surface state charge carriers linearly increases with pressure as the Sm valence approaches 3+. Our results are consistent with the presence of correlation-driven surface states in SmB6 and suggest that the surface Kondo effect persists under pressure to 2 GPa.

Original languageEnglish (US)
Article number245150
JournalPhysical Review B
Issue number24
StatePublished - Jun 15 2022

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics


Dive into the research topics of 'Persistence of correlation-driven surface states in SmB6 under pressure'. Together they form a unique fingerprint.

Cite this