By Xiaoge Liu, Junghyun Park, Ju-Hyung Kang, Hongtao Yuan, Yi Cui, Harold Hwang and Mark Brongersma. Applied Physics Letters 105, 181117 (2014). Figure 3: Hall measurements, carrier density, optical plasma frequency and mobility. Byline corroborated by Stanford SIMES: simes.stanford.edu/publications/quantum?page=21