Bulletin of the American Physical Society
APS March Meeting 2018
Volume 63, Number 1
Monday–Friday, March 5–9, 2018; Los Angeles, California
Session H24: 2D Frustrated Spin Systems: Kagome and HoneycombFocus
|
Hide Abstracts |
Sponsoring Units: GMAG DMP Chair: Alexander Chernyshev, Univ of California - Irvine Room: LACC 403A |
Tuesday, March 6, 2018 2:30PM - 2:42PM |
H24.00001: Phase diagram of the stuffed honeycomb lattice Jyotisman Sahoo, Dmitrii Kochkov, Bryan Clark, Rebecca Flint We introduce the stuffed honeycomb lattice (honeycomb lattice with a superimposed triangular lattice formed by sites at the center of each hexagon) that interpolates between the triangular and the honeycomb lattice. The triangular lattice limit is particularly interesting as DMRG results indicate a clear spin liquid(SL) region whose nature is still unclear. The classical phase diagram has a multi-critical point on the triangular lattice axis, with two new neighboring phases appearing only off axis. Both phases have free classical angles that allow both chiral and non-chiral configurations, with order-by-disorder selecting the non-chiral phases. The quantum phase diagram found via exact diagonalization hosts a large SL region that eats up most of the phase space of the new classical phases; we will present a symmetry analysis of the possible nature of the spin liquids in this region. |
Tuesday, March 6, 2018 2:42PM - 2:54PM |
H24.00002: Emergent Chiral Spin State in the Mott Phase of a Bosonic Kane-Mele-Hubbard Model Kirill Plekhanov, Ivana Vasic, Alexandru Petrescu, Rajbir Nirwan, Guillaume Roux, Walter Hofstetter, Karyn Le Hur Recently, the frustrated XY model for spins-1/2 on the honeycomb lattice has attracted a lot of attention in relation with the possibility to realize a chiral spin liquid state. This model is relevant to the physics of some quantum magnets. Using the flexibility of ultra-cold atoms setups, we propose an alternative way to realize this model through the Mott regime of the bosonic Kane-Mele-Hubbard model. The phase diagram of this model is derived using the bosonic dynamical mean-field theory. Focussing on the Mott phase, we investigate its magnetic and topological properties as a function of frustration using exact diagonalization and bosonic dynamical mean-field theory. We do find an emergent chiral spin state in the intermediate frustration regime. This gapped phase displays a chiral order, breaking spontaneously time-reversal and parity symmetry, but its Chern number is zero. |
Tuesday, March 6, 2018 2:54PM - 3:06PM |
H24.00003: Short range order in the quantum XXZ honeycomb lattice material γ-BaCo2(PO4)2 Harikrishnan Nair, Jesse Brown, Ethan Coldren, Gavin Hester, Martin Gelfand, Andrei Podlesnyak, Kate Ross γ-BaCo2(PO4)2 (γ-BCPO) is a honeycomb-lattice compound with quasi-two-dimensional structure exhibiting short-range ordered (SRO) frustrated magnetism. We have studied hydrothermally synthesized γ-BCPO samples via magnetometry (Χac), specific heat (Cp), x ray and inelastic neutron scattering (INS) experiments. Χac and Cp showed a broad anomaly at ∼ 5 K, with two weak kink features in Cp at TN1 ∼ 6 K and TN2 ∼ 3.5 K. Collinear antiferromagnetic SRO with ordering wavevector |kc| = 0.5 and correlation length ξc = 60 Å and quasi-2D helical SRO with |kh| = 0.25 and ξh = 253 Å form below TN1 and TN2 respectively. Our INS data compares well with linear spin wave theory for two separate parameter regimes of the XXZ J1-J2-J3 model with near neighbor ferromagnetic exchange, J1. Competing further interactions, J2 and J3 place γ-BCPO near regions of high classical degeneracy such as the highly frustrated point, J1/2 = -J2 = J3. Our analysis suggests that γ-BCPO balances near the edge of competing classical phases of the XXZ J1-J2-J3 model, implying that frustration and quantum fluctuations may account for its inability to form a long range order state. |
Tuesday, March 6, 2018 3:06PM - 3:18PM |
H24.00004: Electronic transport in Layered van der Waals Kagome lattice Cluster Compound, Nb3X8 Jiho Yoon, Edouard Lesne, John Sheckelton, Chris Pasco, Tyrel McQueen, Stuart S Parkin, Mazhar Ali Geometrically frustrated materials based on a Kagome lattice have been long studied as promising “Quantum Spin-Liquid” candidates. Of particular interest are metallic spin liquids – theorized to host exotic transport properties including high temperature superconductivity. Recently, the 2D van der Waals cluster compound, Nb3Cl8, which has a Nb Kagome lattice, has been reported as a potential spin liquid material. Due to its insulating behavior, electronic transport properties and their link to the exotic magnetism have not been investigated. Here we report on electronic transport measurements in 10nm-100nm thin flakes of Nb3X8 (X= Cl, Br) in Hall bar geometries, fabricated via standard micromechanical exfoliation techniques combined with photolithography and ion-sputtering deposition. Also, results on using electrostatic charge injection via back-gate and top-gate control to metallize the compound and probe a possibly metallic spin liquid state will be presented. |
Tuesday, March 6, 2018 3:18PM - 3:30PM |
H24.00005: Quantum Spin Liquid with Even Ising Gauge Field Structure on Kagome Lattice Yancheng Wang, Xue-Feng Zhang, Frank Pollmann, Meng Cheng, ZiYang Meng Employing large-scale quantum Monte Carlo simulation, we study the extended XXZ model on kagome lattice. A $\mathbb Z_2$ quantum spin liquid phase with effective even Ising gauge field structure emerges from the delicate balance among three symmetry breaking phases including stripe solid, staggered solid and ferromagnetic phase. This $\mathbb Z_2$ spin liquid is beyond the Lieb-Schultz-Mattis-Oshikawa-Hastings theorem and made possible by the introduction of an extended interaction related to Rokhsar-Kivelson potential. The phase transitions from staggered solid to spin liquid and ferromagnetic phase are first order, so is the transition between stripe solid and ferromagnetic phase. However, the transition between spin liquid and ferromagnetic phase is found to be continuous and belong to 3D XY$^*$ universality class associated with the condensation of spinons, and the transition between spin liquid and stripe solid is seemingly continuous and associated with the condensation of visons. |
Tuesday, March 6, 2018 3:30PM - 3:42PM |
H24.00006: Barlowite: The next quantum spin liquid? Christopher Pasco, Ivo Heinmaa, Ravio Stern, Collin Broholm, Tyrel McQueen Barlowite, Cu4(OH)6BrF, is a newly reported quantum spin liquid (QSL) host material, containing “perfect” kagomé layers separated by interlayer Cu2+ ions, with reports that Zn2+ substitution for Cu2+ induces a QSL ground state. In this talk, we will report on the crystal growth and a comprehensive suite of measurements, including x-ray and neutron diffraction, NMR, specific heat, and magnetization that resolve the ambiguities of the previously reported disorder on the interlayer sites, and provide a quantitative comparison of the physics of Barlowite to other synthetic Cu2+ kagomé minerals. These results pave the way to discovery of S=1/2 kagomé realizations with minimal interlayer coupling effects. |
Tuesday, March 6, 2018 3:42PM - 3:54PM |
H24.00007: Perpendicular susceptibility and geometrical frustration of two-dimensional kagomé Ising antiferromagnet Mahfuza Khatun, Khandker Muttalib, Jeremiah Barry We present perpendicular susceptibility of antiferromagnetic kagomé Ising model obtained from the exact solutions of localized even-number correlations. The susceptibility is calculated with nearest-neighbor pair interactions where strong frustration prevents long-range ordering and with triplet (three-spin) interactions which has no frustration but the system remains disordered down to T=0 temperature. At the zero temperature limit the perpendicular susceptibility for the nearest-neighbor interaction model diverges while it is constant in the triplet interaction model. Both models with and without frustrations show finite residual entropy at the zero temperature limit. Finally, these results are compared with the susceptibilities of two-dimensional kagomé ferromagnetic [1] and triangular antiferromagnetic Ising models. Our findings suggest that the perpendicular susceptibility can be a measure of the degree of frustration of two-dimensional Ising spin systems[2]. |
Tuesday, March 6, 2018 3:54PM - 4:06PM |
H24.00008: Quantum Spin Liquid in a Distorted Kagome Lattice and the Pyrochlore Lattice Li Ern Chern, Kyusung Hwang, Tomonari Mizoguchi, Yejin Huh, Robert Schaffer, Sopheak Sorn, Yong-Baek Kim The Kagome-lattice-based material, volborthite, has been considered as a promising platform for the discovery of exotic quantum ground states. Using projective symmetry group (PSG) analysis and Schwinger boson mean field theory, we explore the possible quantum spin liquid (QSL) and magnetically ordered phases in a two-dimensional nonsymmorphic lattice described by the plane crystallographic group p2gg [1], which is consistent with the spatial anisotropy of the spin model of volborthite derived from density functional theory. We find that the QSL ground state is related to a coplanar incommensurate spiral order, while a closely competing QSL state is related to a spin density wave order. In addition, periodicity enhancement of the two spinon spectrum is observed in the competing QSL state as a result of symmetry fractionalization. Finally, we discuss the correspondence between the bosonic and fermionic QSL states through vison PSG [2]. |
Tuesday, March 6, 2018 4:06PM - 4:18PM |
H24.00009: Electron Doping of Proposed Kagome Quantum Spin Liquid Produces Localized Electrons in Band Gap States but Not Free Electrons Qihang Liu, Tyrel McQueen, Stephan Lany, Alex Zunger Cu3ZnX with X=[(OH)6Cl2] or X=[(OH)6BrF] are Kagome Heisenberg antiferromagnets that display some of the expected quantum spin liquid (QSL) fingerprints, creating the hope that electron doping would enable the long sought high-temperature superconductivity. However, successful insertion of electrons does not necessarily mean free electrons with the ensuing shifted Fermi energy. Z. Kelly et al. recently found that insertion of as much 0.6 Li ions per Cu2+ into Cu3Zn[(OH)6Cl2] does not show the expected metallic conductivity. We have used the modern theory of doping to enquire what happens to electrons inserted into such lattices, particularly the possible interplay between local structural disorder and localization tendencies. Using approaches that correct the self-interaction error we find that whereas the d9 electrons of Cu2+ in the undoped Cu3Zn(OH)6BrF are spread over a broad energy range inside the valence band, upon adding an electron, this broad distribution of levels is bunched into a narrow range of highly localized d10 states inside the band gap. This suggests that the Cu-X manifold has an intrinsic tendency to localize added electrons into a polaronic state. |
Tuesday, March 6, 2018 4:18PM - 4:30PM |
H24.00010: Gapless Spin-Liquid Ground State in the S=1/2 Kagome Antiferromagnet Hai-Jun Liao, Zhi-Yuan Xie, Jing Chen, Zhi-Yuan Liu, Hai-Dong Xie, Rui-Zhen Huang, Bruce Normand, Tao Xiang The defining problem in frustrated quantum magnetism, the ground state of the nearest-neighbor S = 1/2 antiferromagnetic Heisenberg model on the kagome lattice, has defied all theoretical and numerical methods employed to date. We apply the formalism of tensor-network states, specifically the method of projected entangled simplex states, which combines infinite system size with a correct accounting for multipartite entanglement. By studying the ground-state energy, the finite magnetic order appearing at finite tensor bond dimensions, and the effects of a next-nearest-neighbor coupling, we demonstrate that the ground state is a gapless spin liquid. We discuss the comparison with other |
Tuesday, March 6, 2018 4:30PM - 4:42PM |
H24.00011: Effect of the Dzyaloshinskii-Moriya Interactions in the Kagome Heisenberg Antiferromagnet Chih-Yuan Lee, Bruce Normand, Ying-Jer Kao We investigate the effects of Dzyaloshinsky-Moriya (DM) interactions in the kagome antiferromagnet by means of projected entangled simplex states (PESS). Our result shows that the critical value of the DM interaction DC between the gapless spin liquid and the Neel state is D/J ≈0.040, which is only half of the magnitude proposed previously and smaller than the value of D in herbertsmithite. Our work implies that there might be other origins of the spin liquid nature in herbertsmithite. |
Tuesday, March 6, 2018 4:42PM - 4:54PM |
H24.00012: Signatures of gapless fermionic spinons on a strip of the kagome Heisenberg antiferromagnet Ryan Mishmash, Amir M-Aghaei, Bela Bauer, Kirill Shtengel Developing a complete understanding of the ground state properties of spin-1/2 Heisenberg antiferromagnets on the 2D kagome lattice remains a central challenge in the field of frustrated quantum magnetism. Here, we consider the narrowest possible quasi-1D incarnation of the kagome Heisenberg antiferromagnet which consists entirely of corner-sharing triangles. Using large-scale density matrix renormalization group calculations, we identify in this model an extended gapless quantum phase characterized by central charge c=2 and power-law decaying spin and bond-energy correlations which oscillate at tunably incommensurate wave vectors. We argue that this intriguing spin liquid phase can be understood as a marginal instability of a two-band spinon Fermi surface coupled to a U(1) gauge field, an interpretation which we substantiate via bosonization analysis and Monte Carlo calculations on model Gutzwiller variational wave functions. Our results represent one of the first numerical demonstrations of fermionic spinons in a simple SU(2) invariant nearest-neighbor Heisenberg model beyond the strictly 1D (Bethe chain) limit. |
Tuesday, March 6, 2018 4:54PM - 5:06PM |
H24.00013: Investigation of the anomalous Hall effect in Kagome lattice materials with d- and f-electrons Nakheon Sung, Filip Ronning, Joe Thompson, Eric Bauer Recently, a large anomalous Hall effect due to magnetic frustration in the Kagome lattice with a non-collinear antiferromagnetic spin arrangement was observed in the Mn3X (X = Ga, Ge, Sn) compounds. The Ni3Sn crystal structure (P63/mmc) [1-4] of these materials is regarded as an excellent platform for understanding the mechanism of the anomalous Hall effect and may be a candidate for realizing novel topological phenomena in future memory storage devices or in sensors. It is important to discover and characterize new materials with non-collinear magnetic structures to understand the origin of the non-vanishing Berry curvature that leads to the large anomalous Hall effect. Here, we report the physical properties of novel d- and f-electron materials with the Ni3Sn-type crystal structure. |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700