[ { "id": "authors:zkfxy-f6k81", "collection": "authors", "collection_id": "zkfxy-f6k81", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20200928-150652942", "type": "monograph", "title": "Controlling ligand-mediated exchange interactions in periodically driven magnetic materials", "author": [ { "family_name": "Chaudhary", "given_name": "Swati", "clpid": "Chaudhary-Swati" }, { "family_name": "Ron", "given_name": "Alon", "clpid": "Ron-Alon" }, { "family_name": "Hsieh", "given_name": "David", "orcid": "0000-0002-0812-955X", "clpid": "Hsieh-David" }, { "family_name": "Refael", "given_name": "Gil", "clpid": "Refael-G" } ], "abstract": "A periodic drive could alter the effective exchange interactions in magnetic materials. Here, we explore how exchange pathways affect the effective interactions of periodically driven magnetic materials. Aiming to apply Floquet engineering methods to two-dimensional magnetic materials, we consider realistic models and discuss the effect of a periodic drive on ligand-mediated exchange interactions. We show that depending on bond angles and the number of ligand ions involved in the exchange process, drive-induced changes can be very different from those calculated from direct-hopping models considered earlier. We study these effects and find that the presence of ligand ions must be taken into account, especially for TMTCs where ligand ion mediated next-neighbor interactions play a crucial role in determining the magnetic ground state of the system.", "doi": "10.48550/arXiv.2009.00813", "publisher": "arXiv", "publication_date": "2020-09-02" }, { "id": "authors:9126p-wxk25", "collection": "authors", "collection_id": "9126p-wxk25", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20191218-130358489", "type": "monograph", "title": "Evidence for a Parity Broken Monoclinic Ground State in the S = 1/2 Kagom\u00e9 Antiferromagnet Herbertsmithite", "author": [ { "family_name": "Laurita", "given_name": "N. J.", "clpid": "Laurita-N-J" }, { "family_name": "Ron", "given_name": "A.", "orcid": "0000-0002-1840-7824", "clpid": "Ron-Alon" }, { "family_name": "Han", "given_name": "J. W.", "clpid": "Han-J-W" }, { "family_name": "Scheie", "given_name": "A.", "clpid": "Scheie-A" }, { "family_name": "Sheckelton", "given_name": "J. P.", "clpid": "Sheckelton-J-P" }, { "family_name": "Smaha", "given_name": "R. W.", "clpid": "Smaha-R-W" }, { "family_name": "He", "given_name": "W.", "clpid": "He-W" }, { "family_name": "Wen", "given_name": "J.-J.", "clpid": "Wen-J-J" }, { "family_name": "Lee", "given_name": "J. S.", "clpid": "Lee-J-S" }, { "family_name": "Lee", "given_name": "Y. S.", "clpid": "Lee-Y-S" }, { "family_name": "Norman", "given_name": "M. R.", "orcid": "0000-0002-9459-078X", "clpid": "Norman-M-R" }, { "family_name": "Hsieh", "given_name": "D.", "orcid": "0000-0002-0812-955X", "clpid": "Hsieh-David" } ], "abstract": "Nearest-neighbor interacting S = 1/2 spins on the ideal Kagom\u00e9 lattice are predicted to form a variety of novel quantum entangled states, including quantum spin-liquid (SL) and valence bond solid (VBS) phases. In real materials, the presence of additional perturbative spin interactions may further expand the variety of entangled states, which recent theoretical analyses show are identifiable through the spontaneous loss of particular discrete point group symmetries. Here we comprehensively resolve the ground state point group symmetries of the prototypical Kagom\u00e9 SL candidate ZnCu\u2083(OH)\u2086Cl\u2082 (Herbertsmithite) using a combination of optical ellipsometry and wavelength-dependent multi-harmonic optical polarimetry. We uncover a subtle parity breaking monoclinic structural distortion at a temperature above the nearest-neighbor exchange energy scale. Surprisingly, the parity-breaking order parameter is dramatically enhanced upon cooling and closely tracks the build-up of nearest-neighbor spin correlations, suggesting that it is energetically favored by the SL state. The refined low temperature symmetry group greatly restricts the number of viable ground states, and, in the perturbative limit, points toward the formation of a nematic Z\u2082 striped SL ground state - a SL analogue of a liquid crystal.", "doi": "10.48550/arXiv.1910.13606", "publisher": "arXiv", "publication_date": "2019-10-30" }, { "id": "authors:aanht-npz02", "collection": "authors", "collection_id": "aanht-npz02", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140828-155503695", "type": "monograph", "title": "Experimental determination of the microscopic origin of magnetism in parent iron pnictides", "author": [ { "family_name": "Hsieh", "given_name": "D.", "orcid": "0000-0002-0812-955X", "clpid": "Hsieh-David" }, { "family_name": "Xia", "given_name": "Y.", "clpid": "Xia-Yuqi" }, { "family_name": "Wray", "given_name": "L.", "clpid": "Wray-L-A" }, { "family_name": "Qian", "given_name": "D.", "clpid": "Qian-Dong" }, { "family_name": "Gomes", "given_name": "K.", "clpid": "Gomes-K" }, { "family_name": "Yazdani", "given_name": "A.", "clpid": "Yazdani-Ali" }, { "family_name": "Chen", "given_name": "G. F.", "clpid": "Chen-G-F" }, { "family_name": "Luo", "given_name": "J. L.", "clpid": "Luo-J-L" }, { "family_name": "Wang", "given_name": "N. L.", "clpid": "Wang-N-L" }, { "family_name": "Hasan", "given_name": "M. Z.", "clpid": "Hasan-M-Zihad" } ], "abstract": "Like high T_c cuprates, the newly discovered iron based superconductors lie in\nclose proximity to a magnetically ordered parent phase. However, while the\nmagnetic order in parent cuprates is known to derive from a spin-spin local\nsuperexchange interaction, a plethora of experiments including neutron\nscattering have so far been unable to conclusively resolve whether a local\nmoment Heisenberg description applies in parent iron based compounds, or\nwhether magnetism arises from a collective SDW order instability. These two\nalternatives can in principle be distinguished by measuring the low energy\nmomentum-resolved bulk-representative electronic structure of the magnetically\nordered phase. Using a combination of polarization dependent ARPES and STM, we\nhave isolated the complete low-lying bulk representative electronic structure\nof magnetic SrFe_2As_2 with d-orbital symmetry specificity for the first time.\nOur results show that while multiple bands with different iron d-orbital\ncharacter indeed contribute to charge transport, only one pair of bands with\nopposite mirror symmetries microscopically exhibit an itinerant SDW instability\nwith energy scales on the order of 50 meV. The orbital resolved band topology\nbelow T_SDW point uniquely to a nesting driven band hybridization mechanism of\nthe observed antiferromagnetism in the iron pnictides, and is consistent with\nan unusual anisotropic nodal-density-wave state. In addition, these results\nplace strong constraints on many theories of pnictide superconductivity that\nrequire a strict local moment magnetism starting point.", "doi": "10.48550/arXiv.0812.2289", "publisher": "arXiv", "publication_date": "2008-12-12" } ]