The limits of Near Field Immersion Microwave Microscopy evaluated by imaging bilayer graphene Moiré patterns

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 Moiré 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.

suppl. mat included, movies not included and available upon request by email to [email protected]

References in corpus (4)

• Interaction phenomena in graphene seen through quantum capacitance
• Lande g-tensor in semiconductor nanostructures
• Ultra-high-resolution imaging of moiré lattices and superstructures using scanning microwave impedance microscopy under ambient conditions
• Lattice dynamics localization in low-angle twisted bilayer graphene

Cited by in corpus (6)

• Symmetry breaking and anomalous conductivity in a double moiré superlattice
• Raman spectra of twisted bilayer graphene close to the magic angle
• Electron-phonon coupling in a magic-angle twisted-bilayer graphene device
• Torsional Force Microscopy of Van der Waals Moirés and Atomic Lattices
• Johnson-noise-limited cancellation-free microwave impedance microscopy with monolithic silicon cantilever probes
• Anomalous Tip-Sample Distance Behavior on the Tip-Enhanced Raman Spectroscopy of Graphene in Ambient Conditions