Evidence for a spinon Fermi surface in a triangular lattice quantum spin liquid candidate
ORAL
Abstract
In a quantum spin liquid (QSL), highly entangled spins remain disordered down to zero temperature due to strong frustration and quantum fluctuation. Such exotic quantum state can support fractionalized spin excitations called ‘spinon’. In this talk, we present neutron scattering measurements on a QSL candidate YbMgGaO$_4$, a highly frustrated antiferromagnet in which Yb ions form a quasi-two-dimensional triangular lattice. Broad spin excitations are revealed covering a wide region of the Brillouin zone which persists from the lowest measured energy to the zone boundary. The observed continuum is a key characteristic for spinon excitations, providing evidences for a QSL state in YbMgGaO$_4$ that has a spin-1/2 triangular lattice.
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