Emergence of highly degenerate excited states in frustrated magnet MgCr${}_2$O${}_4$

Abstract

High degeneracy in ground states leads to the generation of exotic zero-energy modes, a representative example of which is the formation of molecular spin liquid-like fluctuations in a frustrated magnet. Here we present single-crystal inelastic neutron scattering results for the frustrated magnet MgCr${}_2$O${}_4$, which show that a common set of finite-energy molecular spin excitation modes is sustained in both the liquid-like paramagnetic phase and a magnetically ordered phase with an extremely complex structure. Based on this finding, we propose the concept of high degeneracy in excited states, which promotes local resonant elementary excitations. This concept is expected to have ramifications on our understanding of excitations in many complex systems, including not only spin but also atomic liquids, complex order systems, and amorphous systems.

arXiv comment5 pages, 2 figures

References in corpus (11)

• Quantum Magnetic Excitations from Stripes in Copper-Oxide Superconductors
• Emergent excitations in a geometrically frustrated magnet
• Statics and dynamics of an incommensurate spin order in a geometrically frustrated antiferromagnet CdCr${}_2$O${}_4$
• Electronic band structure and exchange coupling constants in ACr2X4 spinels
• Static Correlation and Dynamical Properties of Tb3+-moments in Tb2Ti2O7 -Neutron Scattering Study-
• Absent pinch points and emergent clusters: further neighbour interactions in the pyrochlore Heisenberg antiferromagnet
• Molecular spin resonance in the geometrically frustrated MgCr2O4 magnet by inelastic neutron scattering
• Observing Monopoles in a Magnetic Analog of Ice
• Molecular spin-orbit excitations in the J_eff = 1/2 frustrated spinel GeCo${}_2$O${}_4$
• Observation of elastic anomalies driven by coexisting dynamical spin Jahn-Teller effect and dynamical molecular spin state in paramagnetic phase of the frustrated MgCr${}_2$O${}_4$$
• Molecular spin-liquid state in spin-3/2 frustrated spinel HgCr${}_2$O${}_4$

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