Bulletin of the American Physical Society
APS March Meeting 2017
Volume 62, Number 4
Monday–Friday, March 13–17, 2017; New Orleans, Louisiana
Session K24: Spectroscopic Signatures of Fractionalized Excitations in Quantum MagnetsInvited
|
Hide Abstracts |
Sponsoring Units: DCMP GMAG Chair: Ioannis Rousochatzakis, University of Minnesota Room: New Orleans Theater C |
Wednesday, March 15, 2017 8:00AM - 8:36AM |
K24.00001: Resonant inelastic X-ray scattering response of the Kitaev spin liquid Invited Speaker: Gábor Halász We propose that resonant inelastic X-ray scattering (RIXS) is an effective probe to detect spin-liquid character in potential material incarnations of the Kitaev spin liquid (such as the honeycomb iridates and ruthenium chloride). Calculating the exact RIXS response of the Kitaev honeycomb model, we find that the fundamental RIXS channels, the spin-conserving (SC) and the non-spin-conserving (NSC) ones, can probe the fractionalized excitations of the Kitaev spin liquid separately. In particular, SC RIXS picks up the gapless Majorana excitations with a pronounced momentum dispersion, while NSC RIXS creates immobile flux excitations, thereby rendering the response weakly momentum dependent. [Preview Abstract] |
Wednesday, March 15, 2017 8:36AM - 9:12AM |
K24.00002: Majorana spectroscopy of Kitaev spin-liquids Invited Speaker: Johannes Knolle Theoretically, some quantum spin liquids (QSLs) -- new topological phases which can occur when quantum fluctuations preclude an ordered state -- are known to exhibit Majorana fermions as quasiparticles arising from fractionalization of spins. Alas, despite much searching, their experimental observation remains elusive. Here, we analyse the dynamical response of a range of Kitaev quantum spin-liquids. Our results test the usefulness of inelastic neutron and light scattering as a probe of these quantum spin liquids: we find that although spin flips fractionalise, the main features of the dynamical spin response nevertheless admit straightforward interpretations in terms of Majorana and flux loop excitations. I will discuss connections to recent experiments on RuCl$_3$. [Preview Abstract] |
Wednesday, March 15, 2017 9:12AM - 9:48AM |
K24.00003: Fingerprints of quantum spin ice in Raman scattering Invited Speaker: Natalia Perkins Quantum spin liquids (QSLs) emerging in frustrated magnetic systems have been a fascinating and challenging subject in modern condensed matter physics for over four decades. In these systems the conventional ordering is suppressed and, instead, unusual behaviors strongly dependent on the topology of the system are observed. The difficulty in the experimental observation of QSLs comes from the fact that unlike the states with broken symmetry, the topological order characteristic of cannot be captured by a local order parameter and thus cannot be detected by local measurements. Identifying QSLs therefore requires reconsideration of experimental probes to find ones sensitive to features characteristic of topological order. The fractionalization of excitations associated with this order can offer signatures that can be probed by conventional methods such as inelastic neutron scattering, Raman or Resonant X-ray scattering experiments. In my talk I will discuss the possibility to use Raman scattering to probe the excitations of Quantum Spin Ice, a model which has long been believed to host a U(1) spin liquid ground state. [Preview Abstract] |
Wednesday, March 15, 2017 9:48AM - 10:24AM |
K24.00004: Scattering continuum and possible fractionalized excitations in RuCl$_{\mathrm{3}}$ Invited Speaker: Luke Sandilands Honeycomb lattice Mott insulators with strong spin-orbit coupling may realize the Heisenberg-Kitaev model. The magnetic interactions contained in this model are intrinsically frustrated and in some parameter regimes a Kitaev quantum spin liquid (QSL) ground state is anticipated. This QSL state is characterized by fractionalized spin excitations that manifest themselves as broad continua in experiment. I will describe Raman scattering measurements on one such spin-orbit coupled Mott insulator, RuCl$_{\mathrm{3}}$. Although this system has a magnetically ordered ground state, the Raman data reveal a continuum of magnetic excitations that persist far above the ordering temperature. The line shape and temperature dependence of this continuum are in fact consistent with the fractionalized excitations expected within the Kitaev model and indicate that RuCl$_{\mathrm{3}}$ may be close to a QSL ground state. [Preview Abstract] |
Wednesday, March 15, 2017 10:24AM - 11:00AM |
K24.00005: Fractionalized Excitations in higher dimensional Iridates Invited Speaker: Peter Lemmens Fractionalization of elementary excitations remains an excotic phenomenon usually limited to 1D and 2D systems. Here we report spectroscopic signatures of fractional excitations in the 3D harmonic-honeycomb iridates beta - and gamma-Li$_{\mathrm{2}}$IrO$_{\mathrm{3}}$ [1]. Our experimental evidence is based on Raman spectroscopic investigations of the polarization and temperature dependence of a scattering continuum, a comparison with earlier investigations of alpha-RuCl$_{\mathrm{3}}$ [2], and a comparison with theoretical modelling of the Kitatev model on different topologies [3]. [1] A. Glamazda, P. Lemmens, S.-H. Do, K.-Y. Choi, Nature Commun. 7, 12286 (2016). [2] L. J. Sandilands, Y. Tian, K. W. Plumb, Y. -J. Kim, and K. S. Burch, PRL 114, 147201 (2015). [3] J. Knolle, G.-W. Chern, D. L. Kovrizhin, R. Moessner, and N. B. Perkins, PRL 113, 187201 (2014). B. Perreault, J. Knolle, N. B. Perkins, and F. J. Burnell, PRB 92, 094439 (2015). [Preview Abstract] |
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