Evidence for a spinon Fermi surface in a triangular-lattice quantum-spin-liquid candidate.
Nature
; 540(7634): 559-562, 2016 Dec 22.
Article
en En
| MEDLINE
| ID: mdl-27919078
ABSTRACT
A quantum spin liquid is an exotic quantum state of matter in which spins are highly entangled and remain disordered down to zero temperature. Such a state of matter is potentially relevant to high-temperature superconductivity and quantum-information applications, and experimental identification of a quantum spin liquid state is of fundamental importance for our understanding of quantum matter. Theoretical studies have proposed various quantum-spin-liquid ground states, most of which are characterized by exotic spin excitations with fractional quantum numbers (termed 'spinons'). Here we report neutron scattering measurements of the triangular-lattice antiferromagnet YbMgGaO4 that reveal broad spin excitations covering a wide region of the Brillouin zone. The observed diffusive spin excitation persists at the lowest measured energy and shows a clear upper excitation edge, consistent with the particle-hole excitation of a spinon Fermi surface. Our results therefore point to the existence of a quantum spin liquid state with a spinon Fermi surface in YbMgGaO4, which has a perfect spin-1/2 triangular lattice as in the original proposal of quantum spin liquids.
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Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Nature
Año:
2016
Tipo del documento:
Article
País de afiliación:
China