An efficient method to generate near-ideal hollow beams of different shapes for box potential of quantum gases.

Ultracold quantum gases are usually prepared in conservative traps for quantum simulation experiments. The atomic density inhomogeneity, together with the consequent position-dependent energy and time scales of cold atoms in traditional harmonic traps, makes it difficult to manipulate and detect the sample at a higher level. These problems are partially solved by optical box traps made of blue-detuned hollow beams.

Dual-Probe Atomic Force Microscopy based on tuning fork probes for critical dimension metrology.

Atomic force microscopy (AFM) is widely used for nano-dimensional metrology in semiconductor manufacturing and metrological system. However, the conventional AFM can't provide accurate CD characterization of nanostructures, due to its top-down configuration and probe-size effect. In this paper, we develop a dual-probe atomic force microscopy (DPAFM).

Atomically Asymmetric Inversion Scales up to Mesoscopic Single-Crystal Monolayer Flakes.

Symmetry is highly relevant with various quantities and phenomena in physics. While the translational symmetry breaks at the edges of two-dimensional hexagonal crystalline flakes, it is usually associated with the breaking of central inversion symmetry that is yet to be observed in terms of physical properties. Here, we report an experiment-theory joint study on in-plane compressed single-crystal monolayer WS flakes.

Interfacial water intercalation-induced metal-insulator transition in NbS/BN heterostructure.

Interfacial engineering, such as molecule intercalation, can modify properties and optimize performance of van der Waals heterostructures and their devices. Here, we investigated the pristine and water molecule intercalated heterointerface of niobium disulphide (NbS) on hexagonal boron nitride (h-BN) (NbS/BN) using advanced atomic force microscopy (AFM), and observed the metal-insulator transition (MIT) of first layer (1L-) of NbS induced by water molecule intercalation. In pristine sample, interfacial charge transfers were confirmed by the direct detection of trapped static charges at the post-exposed h-BN surface, produced by mechanically peeling off the 1L-NbS from the substrate.

Dynamic interfacial mechanical-thermal characteristics of atomically thin two-dimensional crystals.

Owing to the flexible nanoelectronic applications of two-dimensional (2D) materials, further exploration of their nanoscale local mechanical properties and their coupled physical characteristics becomes extremely significant. The puckering effect is a typical micro/nanoscale local frictional characteristic generally in the tip-film-substrate system, which is simultaneously expected to be coupled with a dynamic thermal interfacial response. Here, applying scanning thermal microscopy (SThM), we observed a novel mechanical-thermal coupling effect in monolayer/bilayer MoS2 and WS2 films: puckering deformation can induce the enhancement of interfacial thermal resistance (TR).

Nanoscale charge transfer and diffusion at the MoS/SiO interface by atomic force microscopy: contact injection versus triboelectrification.

Understanding the process of charge generation, transfer, and diffusion between two-dimensional (2D) materials and their supporting substrates is very important for potential applications of 2D materials. Compared with the systematic studies of triboelectric charging in a bulk sample, a fundamental understanding of the triboelectrification of the 2D material/insulator system is rather limited. Here, the charge transfer and diffusion of both the SiO surface and MoS/SiO interface through contact electrification and frictional electrification are investigated systematically in situ by scanning Kelvin probe microscopy and dual-harmonic electrostatic force microscopy.