Chen Li, Lau Jascha A, Schwarzer Dirk, Meyer Jörg, Verma Varun B, Wodtke Alec M
Department of Dynamics at Surfaces, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
Institute for Physical Chemistry, University of Göttingen, 37077 Göttingen, Germany.
Science. 2019 Jan 11;363(6423):158-161. doi: 10.1126/science.aav4278. Epub 2018 Dec 13.
Using a mid-infrared emission spectrometer based on a superconducting nanowire single-photon detector, we observed the dynamics of vibrational energy pooling of carbon monoxide (CO) adsorbed at the surface of a sodium chloride (NaCl) crystal. After exciting a majority of the CO molecules to their first vibrationally excited state (v = 1), we observed infrared emission from states up to v = 27. Kinetic Monte Carlo simulations showed that vibrational energy collects in a few CO molecules at the expense of those up to eight lattice sites away by selective excitation of NaCl's transverse phonons. The vibrating CO molecules behave like classical oscillating dipoles, losing their energy to NaCl lattice vibrations via the electromagnetic near-field. This is analogous to Sommerfeld's description of radio transmission along Earth's surface by ground waves.
我们使用基于超导纳米线单光子探测器的中红外发射光谱仪，观测了吸附在氯化钠（NaCl）晶体表面的一氧化碳（CO）的振动能量汇聚动力学。在将大多数CO分子激发到其首个振动激发态（v = 1）之后，我们观测到了高达v = 27态的红外发射。动力学蒙特卡洛模拟表明，通过选择性激发NaCl的横向声子，振动能量聚集在少数CO分子中，代价是距离多达八个晶格位点的那些分子。振动的CO分子表现得像经典的振荡偶极子，通过电磁近场将其能量损失给NaCl晶格振动。这类似于索末菲对地波沿地球表面进行无线电传输的描述。
