Antiferromagnetism

Scattering

Spin ice

Neutron diffraction

Physics

Neutron scattering

Electron

Dipole

Inelastic neutron scattering

Diffraction

Ising model

Quantum mechanics

Anisotropy

Quantum spin liquid

Magnetic monopole

Atomic physics

Spin polarization

Ground state

Phase (matter)

Spectral line

Multiplet

Condensed matter physics

Pyrochlore

Nuclear physics

Physical Review Letters

Neutron scattering measurements on the pyrochlore magnet Ce2Zr2O7 reveal an unusual crystal field splitting of its lowest J=5/2 multiplet, such that its ground-state doublet is composed of mJ=±3/2, giving these doublets a dipole-octupole (DO) character with local Ising anisotropy. Its magnetic susceptibility shows weak antiferromagnetic correlations with θCW=−0.4(2) K, leading to a naive expectation of an all-in, all-out ordered state at low temperatures. Instead, our low-energy inelastic neutron scattering measurements show a dynamic quantum spin ice state, with suppressed scattering near |Q|=0, and no long-range order at low temperatures. This is consistent with recent theory predicting symmetry-enriched U(1) quantum spin liquids for such DO doublets decorating the pyrochlore lattice. Finally, we show that disorder, especially oxidation of powder samples, is important in Ce2Zr2O7 and could play an important role in the low-temperature behavior of this material.Received 28 November 2018Revised 15 March 2019DOI:https://doi.org/10.1103/PhysRevLett.122.187201© 2019 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasFrustrated magnetismQuantum spin liquidSpin dynamicsPhysical SystemsPyrochloresTechniquesNeutron scatteringCondensed Matter, Materials & Applied Physics

Quantum Spin Ice Dynamics in the Dipole-Octupole Pyrochlore Magnet <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msub><mml:mi>Ce</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi>Zr</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:msub><mml:mi mathvariant="normal">O</mml:mi><mml:mn>7</mml:mn></mml:msub></mml:math>

Quantum Spin Ice Dynamics in the Dipole-Octupole Pyrochlore Magnet Ce2Zr2O7