scholarly journals Thermodynamic, Dynamic, and Transport Properties of Quantum Spin Liquid in Herbertsmithite from an Experimental and Theoretical Point of View

2019 ◽  
Vol 4 (3) ◽  
pp. 75 ◽  
Author(s):  
Vasily R. Shaginyan ◽  
Alfred Z. Msezane ◽  
Miron Ya. Amusia ◽  
John W. Clark ◽  
George S. Japaridze ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Transport Properties ◽  
Optical Conductivity ◽  
Inelastic Neutron Scattering ◽  
Quantum Spin ◽  
Spin Liquid ◽  
Theoretical Point ◽  
Geometrically Frustrated ◽  
State Of Matter ◽  
Quantum Spin Liquid

In our review, we focus on the quantum spin liquid (QSL), defining the thermodynamic, transport, and relaxation properties of geometrically frustrated magnet (insulators) represented by herbertsmithite ZnCu 3 ( OH ) 6 Cl 2 . The review mostly deals with an historical perspective of our theoretical contributions on this subject, based on the theory of fermion condensation closely related to the emergence (due to geometrical frustration) of dispersionless parts in the fermionic quasiparticle spectrum, so-called flat bands. QSL is a quantum state of matter having neither magnetic order nor gapped excitations even at zero temperature. QSL along with heavy fermion metals can form a new state of matter induced by the topological fermion condensation quantum phase transition. The observation of QSL in actual materials such as herbertsmithite is of fundamental significance both theoretically and technologically, as it could open a path to the creation of topologically protected states for quantum information processing and quantum computation. It is therefore of great importance to establish the presence of a gapless QSL state in one of the most prospective materials, herbertsmithite. In this respect, the interpretation of current theoretical and experimental studies of herbertsmithite are controversial in their implications. Based on published experimental data augmented by our theoretical analysis, we present evidence for the the existence of a QSL in the geometrically frustrated insulator herbertsmithite ZnCu 3 ( OH ) 6 Cl 2 , providing a strategy for unambiguous identification of such a state in other materials. To clarify the nature of QSL in herbertsmithite, we recommend measurements of heat transport, low-energy inelastic neutron scattering, and optical conductivity σ ¯ in ZnCu 3 ( OH ) 6 Cl 2 crystals subject to an external magnetic field at low temperatures. Our analysis of the behavior of σ ¯ in herbertsmithite justifies this set of measurements, which can provide a conclusive experimental demonstration of the nature of its spinon-composed quantum spin liquid. Theoretical study of the optical conductivity of herbertsmithite allows us to expose the physical mechanisms responsible for its temperature and magnetic field dependence. We also suggest that artificially or spontaneously introducing inhomogeneity at nanoscale into ZnCu 3 ( OH ) 6 Cl 2 can both stabilize its QSL and simplify its chemical preparation, and can provide for tests that elucidate the role of impurities. We make predictions of the results of specified measurements related to the dynamical, thermodynamic, and transport properties in the case of a gapless QSL.

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

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.

scholarly journals Эволюция квантования Ландау спектра спинонных пар в слабом мотовском диэлектрике La-=SUB=-0.15-=/SUB=-Sm-=SUB=-0.85-=/SUB=-MnO-=SUB=-3+delta-=/SUB=- со спинонной поверхностью Ферми с ростом температуры и напряженности магнитного поля

2021 ◽  
Vol 63 (5) ◽  
pp. 639
Author(s):  
Ф.Н. Буханько ◽  
А.Ф. Буханько
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Quantum Spin ◽  
Spin Liquid ◽  
Quantum Oscillations ◽  
Temperature Range ◽  
Complete Filling ◽  
Weak Magnetic Fields ◽  
Temperature Dependences ◽  
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.

scholarly journals Magnetic field-induced intermediate quantum spin liquid with a spinon Fermi surface

2019 ◽  
Vol 116 (25) ◽  
pp. 12199-12203 ◽  
Author(s):  
Niravkumar D. Patel ◽  
Nandini Trivedi
Keyword(s):  
Magnetic Field ◽  
Fermi Surface ◽  
Intermediate Phase ◽  
Quantum Spin ◽  
Spin Liquid ◽  
Spin Correlations ◽  
Density Matrix Renormalization ◽  
Static Spin ◽  
Kitaev Model ◽  
Quantum Spin Liquid

The Kitaev model with an applied magnetic field in the H∥[111] direction shows two transitions: from a nonabelian gapped quantum spin liquid (QSL) to a gapless QSL at Hc1≃0.2K and a second transition at a higher field Hc2≃0.35K to a gapped partially polarized phase, where K is the strength of the Kitaev exchange interaction. We identify the intermediate phase to be a gapless U(1) QSL and determine the spin structure function S(k) and the Fermi surface ϵFS(k) of the gapless spinons using the density matrix renormalization group (DMRG) method for large honeycomb clusters. Further calculations of static spin-spin correlations, magnetization, spin susceptibility, and finite temperature-specific heat and entropy corroborate the gapped and gapless nature of the different field-dependent phases. In the intermediate phase, the spin-spin correlations decay as a power law with distance, indicative of a gapless phase.

Theoretical and experimental developments in quantum spin liquid in geometrically frustrated magnets: a review

2019 ◽  
Vol 55 (6) ◽  
pp. 2257-2290 ◽  
Author(s):  
V. R. Shaginyan ◽  
V. A. Stephanovich ◽  
A. Z. Msezane ◽  
G. S. Japaridze ◽  
J. W. Clark ◽  
...  
Keyword(s):  
Quantum Spin ◽  
Spin Liquid ◽  
Frustrated Magnets ◽  
Geometrically Frustrated ◽  
Quantum Spin Liquid

scholarly journals Identification of a Kitaev quantum spin liquid by magnetic field angle dependence

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Kyusung Hwang ◽  
Ara Go ◽  
Ji Heon Seong ◽  
Takasada Shibauchi ◽  
Eun-Gook Moon
Keyword(s):  
Magnetic Field ◽  
Quantum Spin ◽  
Majorana Fermion ◽  
Spin Liquid ◽  
Majorana Fermions ◽  
Angle Dependence ◽  
Topological Quantum ◽  
Quantum Science ◽  
Quantum Spin Liquid ◽  
Critical Lines

AbstractQuantum spin liquids realize massive entanglement and fractional quasiparticles from localized spins, proposed as an avenue for quantum science and technology. In particular, topological quantum computations are suggested in the non-abelian phase of Kitaev quantum spin liquid with Majorana fermions, and detection of Majorana fermions is one of the most outstanding problems in modern condensed matter physics. Here, we propose a concrete way to identify the non-abelian Kitaev quantum spin liquid by magnetic field angle dependence. Topologically protected critical lines exist on a plane of magnetic field angles, and their shapes are determined by microscopic spin interactions. A chirality operator plays a key role in demonstrating microscopic dependences of the critical lines. We also show that the chirality operator can be used to evaluate topological properties of the non-abelian Kitaev quantum spin liquid without relying on Majorana fermion descriptions. Experimental criteria for the non-abelian spin liquid state are provided for future experiments.

scholarly journals Magnetic Field Induced Quantum Spin Liquid in the Two Coupled Trillium Lattices of K2Ni2(SO4)3

2021 ◽  
Vol 127 (15) ◽  
Author(s):  
Ivica Živković ◽  
Virgile Favre ◽  
Catalina Salazar Mejia ◽  
Harald O. Jeschke ◽  
Arnaud Magrez ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Quantum Spin ◽  
Spin Liquid ◽  
Quantum Spin Liquid
Sign in / Sign up

Export Citation Format

Share Document