Hostname: page-component-586b7cd67f-g8jcs Total loading time: 0 Render date: 2024-11-26T07:09:02.506Z Has data issue: false hasContentIssue false

Scanning Tunneling Microscopy of Atomic Scale Phonon Standing Waves in Quasi-freestanding WSe2 Monolayers

Published online by Cambridge University Press:  26 February 2016

Igor Altfeder*
Affiliation:
Nanoelectronic Materials Branch, Air Force Research Laboratory, Wright Patterson AFB, OH 45433, USA
Sarah M. Eichfeld
Affiliation:
Department of Materials Science and Engineering and The Center for Two-Dimensional and Layered Materials, The Pennsylvania State University, University Park, PA 16802, USA
Rachel D. Naguy
Affiliation:
Nanoelectronic Materials Branch, Air Force Research Laboratory, Wright Patterson AFB, OH 45433, USA
Joshua A. Robinson
Affiliation:
Department of Materials Science and Engineering and The Center for Two-Dimensional and Layered Materials, The Pennsylvania State University, University Park, PA 16802, USA
Andrey A. Voevodin
Affiliation:
Nanoelectronic Materials Branch, Air Force Research Laboratory, Wright Patterson AFB, OH 45433, USA

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Using scanning tunneling microscopy (STM) we observed atomic scale interference patterns on quasi-freestanding WSe2 islands grown on top of graphene. The bias-independent double atomic size periodicity of these patterns and the sharp Brillouin zone edge revealed by 2D STM Fourier analysis indicate formation of optical phonon standing waves due to scattering on intercalating defects supporting these islands. Standing wave patterns of both synchronized and non-synchronized optical phonons, corresponding to resonant and non-resonant phonon scattering regimes, were experimentally observed. We also found the symmetry breaking effect for individual phonon wave packets, one of the unique features distinguishing phonon standing waves. We show that vibrational and electronic anharmonicities are responsible for STM detection of these patterns. A significant contribution to the interference contrast arises from quantum zero-point oscillations.

Type
Articles
Copyright
Copyright © Materials Research Society 2016 

References

REFERENCES

Fasolino, A., Los, J. H., and Katsnelson, M. I., Nature Materials 6, 858 (2007)Google Scholar
Fransson, J. and Balatsky, A. V., Phys. Rev. B 75, 195337 (2007)Google Scholar
Altfeder, I., Voevodin, A. A., and Roy, A. K., Phys. Rev. Lett. 105, 166101 (2010)Google Scholar
Balandin, A. and Wang, K. L., Phys. Rev. B 58, 1544 (1998)Google Scholar
Rodriguez-Nieva, J. F., Saito, R., Costa, S. D., and Dresselhaus, M. S., Phys. Rev. B 85, 245406 Google Scholar
Klein, M. V., Phys. Rev. 131, 1500 (1963)Google Scholar
Manzano, G., Galve, F., Giorgi, G. L., Hernández-García, E., and Zambrini, R., Sci. Rep. 3, 1439 (2013)CrossRefGoogle Scholar
Gornostyrev, Yu. N., Katsnelson, M. I., Platonov, A. P., Trefilov, A. V., JETP 80, 525 (1995)Google Scholar
Rösch, O., Gunnarsson, O., Phys. Rev. Lett. 92, 146403 (2004)CrossRefGoogle Scholar
Boukhicha, M., Calandra, M., Measson, M. A., Lancry, O., and Shukla, A., Phys. Rev. B 87, 195316 (2013)Google Scholar
Sahin, H., Tongay, S., Horzum, S., Fan, W., Zhou, J., Li, J., Wu, J. and Peeters, F. M., Phys. Rev. B 87, 165409 (2013)CrossRefGoogle Scholar
Eichfeld, S. M., Eichfeld, C. M., Lin, Y. C., Hossain, L., and Robinson, J. A., APL Mat. 2, 092508 (2014)Google Scholar
Eichfeld, S. M. et al., ACS Nano 9, 2080 (2015)CrossRefGoogle Scholar
Zhang, C., Johnson, A., Hsu, C. L., Li, L. J., and Shih, C. K., Nano Lett. 14, 2443 (2014)Google Scholar
Chen, L., Liu, B., Abbas, A. N., Ma, Y., Fang, X., Liu, Y., and Zhou, C., ACS Nano 8, 11543 (2014)Google Scholar
Tonndorf, P. et al., Opt. Express 21, 4908 (2013)CrossRefGoogle Scholar
Wilson, J. A., Yoffe, A. D., Adv. Phys. 18, 193 (1969)Google Scholar
Crawford, J. H. and Slifkin, L. M., Point Defects in Solids: Volume 2, Semiconductors and Molecular Crystals, Plenum Press, New York, 1975 CrossRefGoogle Scholar
Yue, Q., Shao, Z., Chang, S. and Li, J., Nanoscale Research Letters 8, 425( 2013)Google Scholar
Crommie, M. F., Lutz, C. P., and Eigler, D. M., Nature 363, 524 (1993)CrossRefGoogle Scholar
Bollinger, M. V., Lauritsen, J. V., Jacobsen, K. W., Nørskov, J. K., Helveg, S., and Besenbacher, F., Phys. Rev. Lett. 87, 196803 (2001)Google Scholar
Ugeda, M. M. et al., Nature Materials 13, 1091 (2014)Google Scholar
Zhang, L., Liu, K., Wong, A. B., Kim, J., Hong, X., Liu, C., Cao, T., Louie, S. G., Wang, F., and Yang, P., Nano Lett. 14, 6418 (2014)CrossRefGoogle Scholar
Chang, C. H., Fan, X., Lin, S. H., and Kuo, J. L., Phys. Rev. B 88, 195420 (2013)CrossRefGoogle Scholar
Chaos-Cador, L. and Garcıa-Calderon, G., J. Phys. A: Math. Theor. 43, 035301 (2010)Google Scholar
Landau, L. D. and Lifshitz, E. M., Quantum Mechanics, Pergamon, London, 1958 Google Scholar