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DC Field IR Program. Zhiqiang (Jason) Li 2014 Users Committee Meeting Tallahassee, FL October 10-11, 2014. Current Capabilities. IR transmission: up to 35T ( cell 8 ) IR reflectance: up to 17.5T (SCM3) F requency range: 10 -6,000 cm -1 (far-IR to mid-IR) Faraday geometry
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DC Field IR Program Zhiqiang (Jason) Li 2014 Users Committee Meeting Tallahassee, FL October 10-11, 2014
Current Capabilities • IR transmission: up to 35T (cell 8) • IR reflectance: up to 17.5T (SCM3) • Frequency range: 10-6,000 cm-1 (far-IR to mid-IR) • Faraday geometry • Temperature range: 4.2-8K in SCM3, 4.2K in cell 8 • Four samples can be loaded in one cool-down in SCM3 (17.5T magnet) for both transmission and reflectance experiments • Typical noise-to-signal ratio: lower than 0.1% for both reflectance and transmission. (mm sized samples) R(w) IR light B sample T(w)
IR Program Users 16 user groups since 2011 • Phaedon Avouris (IBM) • Ken Burch (Boston college) • SasaDordevic (U. Akron) • Tony Heinz (Columbia University) • Erik Henriksen (Washington University in St. Louis). • ZhigangJiang (Georgia Tech) • Zhiqiang Jason Li (NHMFL) • Jan Musfeldt (U. Tennessee) • Willie Padilla (Boston college) • Dmitry Smirnov (NHMFL) • Sergey Suchalkin (SUNY) • Li-Chun Tung (U. ND) • Yuri Vasilyev (Ioffe Institute) • Feng Wang (UC Berkeley) • XiaodongXu(U. Washington) • ChenglinZhang (U. Tennessee)
Research Areas Explored With IR • Graphene • Quantum wells • Topological insulators • Molecular materials • Multiferroics • 2D transition metal dichalcogenides • Iron-based superconductors • Transition metal oxides
IR User Publications since 2012 1 Nature journals • Zhi-Guo Chen, Zhiwen Shi, Wei Yang, Xiaobo Lu, You Lai, Hugen Yan, Feng Wang, Guangyu Zhang and Zhiqiang Li, “Observation of an intrinsic bandgap and Landau level renormalization in graphene/boron-nitride heterostructures”, Nature Communications 5, 4461 (2014). 3 PRLs • T. V. Brinzari, J. T. Haraldsen, P. Chen, Q.-C. Sun, Y. Kim, L.-C. Tung, A. P. Litvinchuk, J. A. Schlueter, D. Smirnov, J. L. Manson, J. Singleton, and J. L. Musfeldt, Electron-Phonon and Magnetoelastic Interactions in Ferromagnetic Co[N(CN)2]2, Phys. Rev. Lett. 111, 047202 (2013) • J. M. Poumirol, W. Yu, X. Chen, C. Berger, W. A. de Heer, M. L. Smith, T. Ohta, W. Pan, M. O. Goerbig, D. Smirnov, and Z. Jiang, Magnetoplasmons in Quasineutral Epitaxial Graphene Nanoribbons, Phys. Rev. Lett. 110, 246803 (2013) • T. V. Brinzari, P. Chen, Q.-C. Sun, J. Liu, L.-C. Tung, Y. Wang, J. A. Schlueter, J. Singleton, J. L. Manson, M.-H. Whangbo, A. P. Litvinchuk, and J. L. Musfeldt, Quantum Critical Transition Amplifies Magnetoelastic Coupling in Mn[N(CN)2]2, Phys. Rev. Lett. 110, 237202 (2013) 1 Nano letters Hugen Yan, Zhiqiang Li, Xuesong Li, Wenjuan Zhu, Phaedon Avouris, and FengnianXia, Infrared spectroscopy of tunable Dirac terahertz magneto-plasmons in graphene, Nano Lett. 12, 3766 (2012). 5 other journals • S.V. Dordevic et al, Phys. Status Solidi B 251, 1510 (2014). • Ludwig, J. et al, Phys. Rev. B Rapid Commun., 89 (24), 241406 (2014) • Greshnov, A.A. et al, JETP Lett., 97 (2), 106 (2013) • Hugen Yan et al, New Journal of Physics, 14, 125001 (2012). • T. V. Brinzari et al, Phys. Rev. B 86, 214411 (2012)
Feedback from Users • Acquire a new IR spectrometer for SCM 3 • Build new IR probes for SCM3 and cell 8 • Noise issues: 60Hz noise • Gold coating forabsolute reflectance measurements • Polarizer and analyzer
Future Efforts Resistive magnets • Reflectance measurements in cell 7: up to 31T • Gold coating (in situ) --- Absolute reflectance spectra • New IR transmission probe in cell 8 (35T) SCM3 • Build new reflectance probe • Gold coating (in situ) --- Absolute reflectance spectra • Improve existing IR transmission probe • (Different IR windows, bolometer cool down, etc)
Future Efforts Proposed new dedicated IR superconducting magnet 18/20T • Reflectance, transmission • Gold coating (in situ) --- Absolute reflectance spectra • Polarizer and analyzer • Kerr rotation, Faraday rotation • Anisotropic samples • Lower noise • Isolated vacuum space for detector • Integrate amplifying electronics (JFET) close to the detector • Sample temperature: 4.2K—300K • Broad frequency range; multiple detectors