1. The limits of near field immersion microwave microscopy evaluated by imaging bilayer graphene moiré patterns
- Author
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Douglas A. A. Ohlberg, Leonardo C. Campos, Gilberto Medeiros-Ribeiro, Ado Jorio, Eliel G. S. Neto, Diego Tami, Wellington Avelino, Kenji Watanabe, Daniel Miranda, Jhonattan C. Ramirez, Takashi Taniguchi, Fabiano C. Santana, Cassio G. Rego, and Andreij C. Gadelha
- Subjects
Electromagnetic field ,Materials science ,Science ,General Physics and Astronomy ,FOS: Physical sciences ,Near and far field ,02 engineering and technology ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Article ,0103 physical sciences ,Microscopy ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,Nanoscopic scale ,010302 applied physics ,Condensed Matter - Materials Science ,Multidisciplinary ,Condensed Matter - Mesoscale and Nanoscale Physics ,business.industry ,Resolution (electron density) ,Materials Science (cond-mat.mtrl-sci) ,General Chemistry ,Moiré pattern ,021001 nanoscience & nanotechnology ,Scanning probe microscopy ,Optical properties and devices ,Optoelectronics ,0210 nano-technology ,Bilayer graphene ,business ,Microwave ,Sub-wavelength optics - Abstract
Molecular and atomic imaging required the development of electron and scanning probe microscopies to surpass the physical limits dictated by diffraction. Nano-infrared experiments and pico-cavity tip-enhanced Raman spectroscopy imaging later demonstrated that radiation in the visible range can surpass this limit by using scanning probe tips to access the near-field regime. Here we show that ultimate resolution can be obtained by using scanning microwave imaging microscopy to reveal structures with feature sizes down to 1~nm using a radiation of 0.1~m in wavelength. As a test material we use twisted bilayer graphene, which is not only a very important recent topic due to the discovery of correlated electron effects such as superconductivity, but also because it provides a sample where we can systematically tune a superstructure Moir\'e patterns modulation from below one up to tens of nanometers. By analyzing the tip-sample distance dynamics, we demonstrate that this ultimate 10$^8$ probe-to-pattern resolution can be achieved by using liquid immersion microscopy concepts and exquisite force control exerted on nanoscale water menisci., Comment: suppl. mat included, movies not included and available upon request by email to gilberto@dcc.ufmg.br
- Published
- 2020