Imaging the nanoscale phase separation in vanadium dioxide thin films at terahertz frequencies
| Autor: | Alexander McLeod, Loic Anderegg, Tetiana Slusar, Dimitri Basov, H. T. Stinson, M. Rozenberg, Ran Jing, Aaron Sternbach, A. Mueller, O. Najera, Hyun-Tak Kim |
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| Přispěvatelé: | Laboratoire de Physique des Solides (LPS), Centre National de la Recherche Scientifique (CNRS)-Université Paris-Sud - Paris 11 (UP11), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Phase transition
Physics - Instrumentation and Detectors Hubbard model Terahertz radiation Science General Physics and Astronomy FOS: Physical sciences Physics::Optics 02 engineering and technology 01 natural sciences General Biochemistry Genetics and Molecular Biology Article law.invention Condensed Matter - Strongly Correlated Electrons Optical microscope law 0103 physical sciences Mesoscale and Nanoscale Physics (cond-mat.mes-hall) [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det] Thin film 010306 general physics lcsh:Science Nanoscopic scale Physics Multidisciplinary Strongly Correlated Electrons (cond-mat.str-el) Condensed Matter - Mesoscale and Nanoscale Physics business.industry Scattering digestive oral and skin physiology General Chemistry Instrumentation and Detectors (physics.ins-det) 021001 nanoscience & nanotechnology [PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph] Optoelectronics Near-field scanning optical microscope lcsh:Q Condensed Matter::Strongly Correlated Electrons 0210 nano-technology business Optics (physics.optics) Physics - Optics |
| Zdroj: | Nature Communications, Vol 9, Iss 1, Pp 1-9 (2018) Nature Commun. Nature Commun., 2018, 9, pp.3604. ⟨10.1038/s41467-018-05998-5⟩ Nature Communications |
| DOI: | 10.1038/s41467-018-05998-5⟩ |
| Popis: | Vanadium dioxide (VO2) is a material that undergoes an insulator–metal transition upon heating above 340 K. It remains debated as to whether this electronic transition is driven by a corresponding structural transition or by strong electron–electron correlations. Here, we use apertureless scattering near-field optical microscopy to compare nanoscale images of the transition in VO2 thin films acquired at both mid-infrared and terahertz frequencies, using a home-built terahertz near-field microscope. We observe a much more gradual transition when THz frequencies are utilized as a probe, in contrast to the assumptions of a classical first-order phase transition. We discuss these results in light of dynamical mean-field theory calculations of the dimer Hubbard model recently applied to VO2, which account for a continuous temperature dependence of the optical response of the VO2 in the insulating state. The insulator-to-metal transition in vanadium dioxide still has many unexplored properties. Here the authors use multi-modal THz and mid-IR nano-imaging to examine the phase transition in VO2 thin films, and discuss the unexpectedly smooth transition at THz frequencies in the context of a dimer Hubbard model. |
| Databáze: | OpenAIRE |
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