Bulletin of the American Physical Society
86th Annual Meeting of the APS Southeastern Section
Volume 64, Number 19
Thursday–Saturday, November 7–9, 2019; Wrightsville Beach, North Carolina
Session G01: Low-dimensional Materials and Magneto-optics |
Hide Abstracts |
Chair: Jian Liu, University of Tennessee Room: Holiday Inn Resort Causeway/Masonboro |
Friday, November 8, 2019 2:00PM - 2:30PM |
G01.00001: Probing Local Interactions at the Nanoscale Invited Speaker: Yohannes Abate Interactions at the nanometer length scale in hard and soft condensed matter give rise to intriguing phases in correlated electron materials, lead to the design of exotic metamaterials, and offer enormous opportunities for the development of novel optoelectronic devices. I will give representative examples of high-resolution probing of fundamental nanoscale physical phenomena and interactions in quantum materials at infrared (IR), terahertz (THz), and optical frequencies. At mid IR frequencies, we probe the local interaction of a heterostructure of isotopically enriched hexagonal boron nitride (hBN) in direct contact with the phase-change material (PCM) single-crystal vanadium dioxide (VO$_{\mathrm{2}})$ and demonstrate a reconfigurable hyperbolic metasurface. At THz frequencies, in the truly THz frequency range 13 cm$^{\mathrm{-1}}$ - 60 cm$^{\mathrm{-1}}$ we probe and quantify local charge carriers in correlated and complex oxides and heterogeneously doped semiconductors. In the visible spectral range, we probe propagating surface waves that are excited at sharp edges of layered transition metal dichalcogenides (TMDC) such as molybdenum disulfide and tungsten diselenide. [Preview Abstract] |
Friday, November 8, 2019 2:30PM - 3:00PM |
G01.00002: Chirality-induced spin-Hall magnetoresistance in 2D chiral hybrid perovskites Invited Speaker: Dali Sun 2D ferromagnetism is an emerging field in spintronics applications. The use of generic 2D ferromagnetic materials, however, suffers of the so-called ‘superparamagnetic limit’, which imposes restrictions on the size and dimension of the ferromagnetic component used in spintronics devices. The recent discovery of the Chiral-Induced Spin Selectivity (CISS) effect offers a possibility to generate spin angular momentum by replacing the ferromagnetic component with chiral systems, e.g., chiral (left- or right-handed) molecules and their assemblies lacking inversion symmetry. As a result of the CISS effect, the chiral materials can produce an effective magnetic field at room temperature, which direction is determined by the left or right chirality, circumventing the ‘superparamagnetic limit’. Here, we report the observation of a large chiral-induced magnetic field up to 4 Tesla in solution-processed, 2D-layered, organic-inorganic hybrid perovskites incorporating chiral molecule ligands. Such chiral-induced magnetic field is probed by measuring the resistance through an attached platinum layer, analogous with the spin- Hall magnetoresistance (SMR). We found a substantial angular dependent chirality-induced SMR that agrees well with theoretical models. By sweeping the magnetic field, the SMR reveals a clear hysteresis depending upon the chirality of 2D perovskites, which could be used to quantify the effective magnetic field strength produced via the CISS effect. Incorporating the chiral molecules into a 2D layered hybrid perovskite framework offers a versatile platform for designing 2D ferromagnetic materials at room temperature. \\ \\ In collaboration with: Eric Vetter, North Carolina State University, Yan Liang, University of North Carolina at Chapel Hill, Yuzan Xiong, Oakland University, Shulei Zhang, Zhizhi Zhang, Oakland University, Yi Li, Oakland University and Argonne National Laboratory, Hongwei Qu, Oakland University, Valentine Novosad, Axel Hoffmann, Argonne National Laboratory, Wei You, University of North Carolina at Chapel Hill, Wei Zhang, Oakland University. \\ Acknowledgement: E.V. and D.S. were thankful for the start-up support provided by North Carolina State University and NC State-Nagoya Collaboration Grant. Work at Oakland University was supported by AFOSR under no. FA9550-19-1-0254. Work at Argonne was supported by the Department of Energy, Office of Science, Materials Science and Engineering Division. [Preview Abstract] |
Friday, November 8, 2019 3:00PM - 3:30PM |
G01.00003: Low-energy Spectroscopy on Magnetic Materials Invited Speaker: Komalavalli Thirunavukkuarasu Low-energy spectroscopy at extreme conditions opens door to discovery and understanding of novel phenomena in condensed matter physics. Combining spectroscopy with one or more external parameters such as low temperature, high pressure and high magnetic fields, allows us to continuously induce perturbations to probe properties of materials across their phase diagram. Among low-energy spectroscopic techniques, THz, infrared (IR) spectroscopy, Raman scattering and electron paramagnetic resonance (EPR) spectroscopy are powerful tools to investigate the fundamental energy scales involved in the interplay of charge, spin, lattice and orbital degrees of freedom. Recently, we employed magneto-Raman spectroscopy on two different kinds of magnetic materials; the first compound being the Shastry-Sutherland compound SrCu2(BO3)2 and the second compound is the multi-ferroic metal organic framework [(CH3)2NH2]Co(HCOO)3. We performed magneto-Raman spectroscopic measurements are those two compounds at magnetic fields up to 45 T to investigate the nature of magnetoelastic coupling in these magnetic materials. In this talk, I will present our recent results in detail and explain their implications. This work has been performed at the user facilities in the National High Magnetic Field Laboratory (NHMFL), Tallahassee. The NHMFL is supported by the National Science Foundation through NSF/DMR-1644779 and the state of Florida. The project is also funded by DoN HBCU/MI program award {\#} N000141713061 [Preview Abstract] |
Friday, November 8, 2019 3:30PM - 4:00PM |
G01.00004: Giant antiferromagnetic response in a two-dimensional spin-orbit Mott insulator Invited Speaker: Lin Hao Antiferromagnetic (AFM) materials started to gain traction owing the advantages of reliability, ultrafast dynamics, etc. in spintronic applications. In this regard, Mott insulators can be an appealing candidate because of the robust AFM ground state due to the strong electron-electron correlation. Moreover, exploring AFM order is fundamentally important for understanding emergent phenomena, like high-Tc superconductivity and quantum criticality. In our recent work, we investigated AFM order in layered iridates, which is a newly established Mott system similar to cuprates but features a strong spin-orbit coupling. By building the spin-orbit Mott insulators as superlattices composed of perovskite SrIrO3 and SrTiO3, we gained controllability in the strength and sign of interlayer exchange interaction. This enables one to reach the two-dimensional limit of the antiferromagnet, where the ordering temperature is only governed by magnetic anisotropy. The two-dimensional antiferromagnet preserves a hidden SU(2) symmetry, which was first proposed in cuprates but never experimentally realized. More specifically, model analysis reveals that Dzyaloshinskii--Moriya interaction in the square-lattice magnet does not contribute to the spin anisotropy. The extremely strong two-dimensional critical fluctuations enable us to achieve giant AFM responses to sub-tesla uniform external fields. The observed field-induced logarithmic increase of the AFM ordering demonstrates a new pathway for designing efficient AFM spintronics. These results were recently published on Phys. Rev. Lett. [119,027204, (2017)] and Nat. phys. [14, 806--810 (2018)]. [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