Exploiting the Momentum Distribution in Atomically Confined Plasmonic Fields by Inelastic Scatterings

Abstract

The utilization of atomically confined plasmonic fields has revolutionized the imaging technique. According to the fundamental position− momentum uncertainty principle, such a narrow spatial distribution certainly leads to a broad momentum distribution in the fields, which has however been overlooked. Here we propose a novel exploitation for the momentum distribution by adaptively satisfying the conservation law of momentum in inelastic Raman scatterings in periodic systems, providing a unique optical means of directly measuring the whole phonon dispersions. The proposed technique is particularly useful for measuring phonon dispersions of low-dimensional hydrogen-rich materials, which are completely inaccessible via other techniques. The numerical results for a single alltrans polyacetylene chain demonstrate that all phonon dispersion branches can be conclusively measured from their Raman images for the first time. Our findings highlight a unique advantage of the emerging momentum-based nanophotonics and open the door for exploiting highly confined plasmonic fields in another dimension.

Theoretical and computational methods for tip- and surface-enhanced Raman scattering

“…20a). 169 This result is a manifestation of the fundamental position-momentum uncertainty principle in quantum mechanics. 60,62 Fig.…”

“…20b). 169,172 On the other hand, when a 2.5 Å SCP was focused on the central CQC bond of a 36-unit t-PA chain, the resulting Raman spectrum exhibits three bundles of vibrational bands, where not only the G-modes of v 2 , v 3 (C-H bending), and v 4 (marked as colored stars in Fig. 20b) but also other modes that have different phases are observable, which reveals the breakdown of the k = 0 selection rule.…”

“…This result should be attributed to the adaptive satisfaction of the energy and (pseudo)momentum conservation laws in the inelastic scatterings of the SCP that has a broad momentum distribution. 169 The emergence of the non-G-modes provides a probability to determine the phonon dispersion of t-PA which is a representative system of the low-dimensional hydrogen-rich materials. To this end, the frequency and the wavevector of individual vibrations should be measured.…”

Atomically Dispersed Metal‐Nitrogen‐Carbon Electrocatalysts for the Oxygen Reduction Reaction

“…In order to reduce costs and improve atomic utilization efficiency, significant attention has been directed towards single‐atom electrocatalysts in recent years [8–14] . Among these, metal‐nitrogen‐carbon (M‐N‐C) electrocatalysts have attracted extensive attention because of their well‐define catalytic sites, which is conducive to the mechanistic investigation of electrocatalytic reaction through density functional theory and in situ characterization techniques.…”

Accurate Simulations of Scanning Tunneling Microscope: Both Tip and Substrate States Matter

“…Owing to the clear physical interpretation and easy implementation, methods under the TH approximations have been generally adopted in current investigations. In other words, although theories for other STM-based techniques, e.g., tip-enhanced Raman scattering, were rapidly developed in the past decade, ,,,− nowadays, theoretical simulations of STM itself are extensively focused on the electronic structures of the substrates. Nevertheless, overlooking the details of the tip states will certainly lead to difficulty in interpreting some advanced high-resolution STM experimental results.…”