scholarly journals Microcavity phonon polaritons from the weak to the ultrastrong phonon–photon coupling regime

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
María Barra-Burillo ◽  
Unai Muniain ◽  
Sara Catalano ◽  
Marta Autore ◽  
Fèlix Casanova ◽  
...  

AbstractStrong coupling between molecular vibrations and microcavity modes has been demonstrated to modify physical and chemical properties of the molecular material. Here, we study the less explored coupling between lattice vibrations (phonons) and microcavity modes. Embedding thin layers of hexagonal boron nitride (hBN) into classical microcavities, we demonstrate the evolution from weak to ultrastrong phonon-photon coupling when the hBN thickness is increased from a few nanometers to a fully filled cavity. Remarkably, strong coupling is achieved for hBN layers as thin as 10 nm. Further, the ultrastrong coupling in fully filled cavities yields a polariton dispersion matching that of phonon polaritons in bulk hBN, highlighting that the maximum light-matter coupling in microcavities is limited to the coupling strength between photons and the bulk material. Tunable cavity phonon polaritons could become a versatile platform for studying how the coupling strength between photons and phonons may modify the properties of polar crystals.

2009 ◽  
Vol 83-86 ◽  
pp. 953-958
Author(s):  
Ching Yen Ho ◽  
Yu Hsiang Tsai ◽  
Mao Yu Wen

Nanometer-sized particles possess characteristic physical and chemical properties different from those of bulk materials due to an increase in surface-to-volume ratios as well as of confinement of electrons, excitons, and photons into small volumes. Therefore it is worthwhile to discuss the thermal behaviours of powders constituted by nanometer-sized particles. The heat transfer in the powder composed of nanoparticles is experimentally investigated in this paper. The understanding for thermal properties of the powder is advantageous to the advancement of the processing technologies such as laser cladding, laser sintering, powder metallurgy and its other applications. The powder is wrapped up in the slender tube made of insulating material. One end of the slender tube filled with powder is maintained at temperature 0°C and the other end is kept at room temperature. The temperature histories at two different locations in the slender tube are recorded using thermal couples. The results show that the thermal diffusivity in the powder composed of nanoparticles is larger than that in bulk material. The pressure on the Al powders enhances the rate of heat transport due to the increase of contact area for thermal conduction.


2000 ◽  
Vol 648 ◽  
Author(s):  
U. Heiz ◽  
S. Abbet ◽  
H. Häkkinen ◽  
U. Landman

AbstractCluster-assembled materials open fascinating new routes for tuning physical and chemical properties by changing cluster size and often these materials behave completely differently than their bulk analogues. By depositing gas phase cluster cations on various surfaces, cluster model catalysts are fabricated, which exhibit remarkable catalytic activity. While inert as bulk material, gold cluster catalysts oxidize carbon monoxide with Au8 to be the smallest active size. In contrast to the high selectivity of Pd(111) surfaces for the cyclotrimerization of acetylene, small supported Pdn clusters reveal a strongly size-dependent selectivity for the polymerization of acetylene and catalyze the cyclotrimerization as well as the hydrogenation of the formed intermediate C4H4.


MRS Bulletin ◽  
2006 ◽  
Vol 31 (2) ◽  
pp. 87-94 ◽  
Author(s):  
Paul J.A. Kenis ◽  
Abraham D. Stroock

AbstractOver the last two decades, our ability to create networks of fluidic channels of submillimeter or even sub-micrometer diameters has led to a wide range of microchemical applications. Whereas early efforts were directed toward the development of microanalysis systems, in more recent times the development of microreactors and tools for biotechnology and basic biological studies has emerged. This issue of MRS Bulletin highlights the many different ways in which material properties are crucial in the fabrication, assembly, and operation of micro- and nanofluidic systems. Choice-of-material considerations range from an assessment of whether a desired channel design can be microfabricated in a certain material to whether the material is compatible with the operating conditions (i.e., pressure, temperature) and the chemical composition (solvent, solutes) of the fluid used. Moreover, in certain cases, specific surface or bulk material properties can be used to the benefit of the application of the device. In the development of today's wide range of integrated micro- and nanofluidic applications, a common challenge emerges: meeting the often contradictory set of constraints imposed on the physical and chemical properties of materials by the envisioned applications. This issue reviews these challenges and their solutions and provides an outlook on how the ingenious use of existing and new materials can spur the development of ever more sophisticated micro- and nanofluidic systems.


1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.


Author(s):  
Mehmet Sarikaya ◽  
Ilhan A. Aksay

Biomimetics involves investigation of structure, function, and methods of synthesis of biological composite materials. The goal is to apply this information to the design and synthesis of materials for engineering applications.Properties of engineering materials are structure sensitive through the whole spectrum of dimensions from nanometer to macro scale. The goal in designing and processing of technological materials, therefore, is to control microstructural evolution at each of these dimensions so as to achieve predictable physical and chemical properties. Control at each successive level of dimension, however, is a major challenge as is the retention of integrity between successive levels. Engineering materials are rarely fabricated to achieve more than a few of the desired properties and the synthesis techniques usually involve high temperature or low pressure conditions that are energy inefficient and environmentally damaging.In contrast to human-made materials, organisms synthesize composites whose intricate structures are more controlled at each scale and hierarchical order.


2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.


Author(s):  
O.S. Bezuglova ◽  

Rostov Region belongs to the highly protected natural territories characterized by the continuous plowing. There territories are the only reserves with the soils preserved in their natural state. However, these areas often lack detailed information about the soils quality and composition. Surveying soils on these territories is crucial for determination of their basic physical and chemical properties. The resulted compilation of soil maps could lay a foundation for creating the Red Book of Soils and the formation of a section in the soil-geographical database of the Russian Federation. Subsequently, such information can be used as a background data for the main types of soils in the region. It will be also valuable during monitoring and justification of conservation measures.


Sign in / Sign up

Export Citation Format

Share Document