Anomalous Quantum Oscillations in a Heterostructure of Graphene on a Proximate Quantum Spin Liquid

Measurements of the magnetization temperature dependences of La0.15Sm0.85MnO3+δ in the temperature range 4.2 - 100 K revealed a threshold magnetization feature near the temperature Td 50 K, associated with the existence of a small pseudogap Δe in the electron spectrum, which is characteristic of a weak Mott dielectric. An increase in the strength H of the external magnetic field leads to suppression of the dielectric pseudogap Δe, an increase in the density of states of free charge/ spin carriers at EF, and transformation of the charge/spin density waves fragments. A quantization of the pairs spectrum of the low-energy magnetic excitations of a Z2 quantum spin liquid in the form of spinon-gauge field composite quasiparticles was found in the temperature range 4.2 - 12 K. Formation of a continuous spectrum of the quantum spin liquid excitations in the regime of “weak magnetic fields” Н = 100 Oe, 350 Oe, 1 kOe is explained within the framework of the Landau quantization models of the spectrum of composite quasiparticles with fractional values of the factor ν filling of three overlapping Landau zones.. In the regime of a “strong external magnetic field” H = 3.5 kOe, the new quantum oscillations of the temperature dependences of the magnetization of an incompressible spinon liquid were founded in the form of three narrow steps (plateaus) corresponding to the complete filling of non-overlapping Landau zones with integer values of the filling factor by spinons.

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A possible quantum spin liquid in a spin-orbital entangled 2d magnet

10.36471/jccm_november_2017_02 ◽

2017 ◽

Keyword(s):

Quantum Spin ◽

Spin Liquid ◽

Spin Orbital ◽

Quantum Spin Liquid

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Correlation holes and slow dynamics induced by fractional statistics in gapped quantum spin liquids

Nature Communications ◽

10.1038/s41467-021-21495-8 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Oliver Hart ◽

Yuan Wan ◽

Claudio Castelnovo

Keyword(s):

Transport Properties ◽

Realistic Model ◽

Feedback Mechanism ◽

Quantum Spin ◽

Spin Liquid ◽

Spin Liquids ◽

Slow Dynamics ◽

Temperature Dependent ◽

Quantum Spin Liquids ◽

Quantum Spin Liquid

AbstractRealistic model Hamiltonians for quantum spin liquids frequently exhibit a large separation of energy scales between their elementary excitations. At intermediate, experimentally relevant temperatures, some excitations are sparse and hop coherently, whereas others are thermally incoherent and dense. Here, we study the interplay of two such species of quasiparticle, dubbed spinons and visons, which are subject to nontrivial mutual statistics – one of the hallmarks of quantum spin liquid behaviour. Our results for $${{\mathbb{Z}}}_{2}$$ Z 2 quantum spin liquids show an intriguing feedback mechanism, akin to the Nagaoka effect, whereby spinons become localised on temperature-dependent patches of expelled visons. This phenomenon has important consequences for the thermodynamic and transport properties of the system, as well as for its response to quenches in temperature. We argue that these effects can be measured in experiments and may provide viable avenues for obtaining signatures of quantum spin liquid behaviour.

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Gapless Quantum Spin Liquid in the Triangular System Sr3CuSb2O9

Physical Review Letters ◽

10.1103/physrevlett.125.267202 ◽

2020 ◽

Vol 125 (26) ◽

Author(s):

S. Kundu ◽

Aga Shahee ◽

Atasi Chakraborty ◽

K. M. Ranjith ◽

B. Koo ◽

...

Keyword(s):

Quantum Spin ◽

Spin Liquid ◽

Triangular System ◽

Quantum Spin Liquid

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Giant phonon anomalies in the proximate Kitaev quantum spin liquid α-RuCl3

Nature Communications ◽

10.1038/s41467-021-23826-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Haoxiang Li ◽

T. T. Zhang ◽

A. Said ◽

G. Fabbris ◽

D. G. Mazzone ◽

...

Keyword(s):

Acoustic Phonon ◽

Energy Scale ◽

Quantum Spin ◽

Majorana Fermion ◽

Spin Liquid ◽

Optical Phonons ◽

Large Intensity ◽

Topological Quantum ◽

Topological State ◽

Quantum Spin Liquid

AbstractThe Kitaev quantum spin liquid epitomizes an entangled topological state, for which two flavors of fractionalized low-energy excitations are predicted: the itinerant Majorana fermion and the Z2 gauge flux. It was proposed recently that fingerprints of fractional excitations are encoded in the phonon spectra of Kitaev quantum spin liquids through a novel fractional-excitation-phonon coupling. Here, we detect anomalous phonon effects in α-RuCl3 using inelastic X-ray scattering with meV resolution. At high temperature, we discover interlaced optical phonons intercepting a transverse acoustic phonon between 3 and 7 meV. Upon decreasing temperature, the optical phonons display a large intensity enhancement near the Kitaev energy, JK~8 meV, that coincides with a giant acoustic phonon softening near the Z2 gauge flux energy scale. These phonon anomalies signify the coupling of phonon and Kitaev magnetic excitations in α-RuCl3 and demonstrates a proof-of-principle method to detect anomalous excitations in topological quantum materials.

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