Field-driven gapless spin liquid in the spin-1 Kitaev honeycomb model

oleh: CiarĂ¡n Hickey, Christoph Berke, Panagiotis Peter Stavropoulos, Hae-Young Kee, Simon Trebst

Format: Article
Diterbitkan: American Physical Society 2020-06-01

Deskripsi

Recent proposals for spin-1 Kitaev materials, such as honeycomb Ni oxides with heavy elements of Bi and Sb, have shown that these compounds naturally give rise to antiferromagnetic (AFM) Kitaev couplings. Conceptual interest in such AFM Kitaev systems has been sparked by the observation of a transition to a gapless U(1) spin liquid at intermediate field strengths in the AFM spin-1/2 Kitaev model. However, all hitherto known spin-1/2 Kitaev materials exhibit ferromagnetic bond-directional exchanges. Here we discuss the physics of the spin-1 Kitaev model in a magnetic field and show, by extensive numerical analysis, that for AFM couplings it exhibits an extended gapless quantum spin liquid at intermediate field strengths. The close analogy to its spin-1/2 counterpart suggests that this gapless spin liquid is a U(1) spin liquid with a neutral Fermi surface that gives rise to enhanced thermal transport signatures.