Broadband microwave electrical transport spectroscopy for two-dimensional material systems
Antonio Levy, Neil M. Zimmerman
In recent years, interesting materials have emerged which are only available as µm-scale flakes, and whose novel physics might be better understood through broadband microwave spectroscopy; examples include twisted bilayer graphene , 2D materials in which many-body phases are observed , and artificial lattices for analog quantum simulations . Most previous techniques are unfortunately not sensitive for flakes below mm lateral sizes. We propose a simple technique which does not require sophisticated sample preparation nor Ohmic contact, and show through theory and simulations that one will be able to qualitatively measure spectral features of interest, and quantitatively measure the frequency-dependent complex conductivity.  Y. Cao, V. Fatemi, S. Fang, K. Watanabe, T. Taniguchi, E. Kaxiras and P. Jarillo-Herrero, "Unconventional superconductivity in magic-angle graphene superlattices," Nature, vol. 556, no. 7699, pp. 43-50, 2018.  S. Chen, R. Ribeiro-Palau, K. Yang, T. Taniguchi, J. Hone, M. O. Goerbig and C. R. Dean, "Competing Fractional Quantum Hall and Electron Solid Phases in Graphene," Physical Review Letters, vol. 122, no. 2, p. 026802, 2019.  J. Salfi, J. A. Mol, R. Rahman, G. Klimeck, M. Y. Simmons, L. C. L. Hollenberg and S. Rogge, "Quantum simulation of the Hubbard model with dopant atoms in silicon," Nature communications, vol. 7, pp. 1-6, 2016.
and Zimmerman, N.
Broadband microwave electrical transport spectroscopy for two-dimensional material systems, Journal of Applied Physics, [online], https://doi.org/10.1063/5.0087285, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=933916
(Accessed August 18, 2022)