Scanning probe microscopy

Scanning NV center magnetometry enables imaging of weak magnetic fields at the nanoscale. Huxter et al. achieve an order-of-magnitude improvement in sensitivity by converting a spatial field gradient into an AC field by mechanical oscillations of the sensor, and image stray fields from atomic steps in an antiferromagnet.

Hyperbolic phonon polaritons – mixed states of photons and anisotropic lattice vibrations – offer appealing properties for nanophotonic applications. Here, the authors show that the plasmon-phonon hybridization upon electronic doping in graphene/α-MoO3 heterostructures can induce topological transitions of the polariton wavefront.

The strained topology of [n]paracyclophenylenes ([n]CPPs) typically prevents their π sysytem from being extended, but now the formation of a planar π-extended CPP has been achieved through a bottom-up on-surface synthesis approach. The planar π-extended [12]CPP produced by this method is a nanographene featuring an all-armchair edge, which leads to delocalized electronic states around the entire ring.

Light harvesting in photosynthesis and photovoltaics may rely on quantum-coherent energy transfer, but experimental verification is hindered by the lossy nature of the molecular systems. Subnanometre-resolved electroluminescence spectroscopy now reveals wavelike intermolecular electronic energy transfer through quantum coherence in artificially constructed donor–acceptor heterodimers at the single-molecule level.

Positioning and trapping single atoms at specific sites of surfaces is a challenging goal that can advance the development of single atom devices. Here the authors demonstrate that single Ag atoms are trapped inside corner holes of the Si(111)-7×7 surface for more than 4 days at room temperature, and suggest that this behavior may be shared by other elements.