We present a novel view of the standard model of tunneling two level systems (TLSs) to explain the puzzling universal value of a quantity, C∼3×10^{-4}, that characterizes phonon scattering in glasses below 1 K as reflected in thermal conductivity, ultrasonic attenuation, internal friction, and the change in sound velocity. Physical considerations lead to a broad distribution of phonon-TLS couplings that (1) exponentially renormalize tunneling matrix elements, and (2) reduce the TLS density of states through TLS-TLS interactions. We find good agreement between theory and experiment for a variety of individual glasses.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1103/PhysRevLett.124.075902 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Combining Brillouin Light Scattering Spectroscopy and Machine-Learned Interatomic Potentials to Probe Mechanical Properties of Metal-Organic Frameworks.
J Phys Chem Lett
January 2025
Institute of Bioproducts and Paper Technology, Graz University of Technologyy, Inffeldgasse 23, 8010 Graz, Austria.
The mechanical properties of metal-organic frameworks (MOFs) are of high fundamental and practical relevance. A particularly intriguing technique for determining anisotropic elastic tensors is Brillouin scattering, which so far has rarely been used for highly complex materials like MOFs. In the present contribution, we apply this technique to study a newly synthesized MOF-type material, referred to as GUT2.
View Article and Find Full Text PDFEu-Substituents-Induced Modifications in the Thermoelectric Properties of the Zintl Phase BaEuZnSb System.
Molecules
January 2025
Department of Chemistry, Chungbuk National University, Cheongju 28644, Chungbuk, Republic of Korea.
Four quaternary Zintl phase thermoelectric (TE) materials belonging to the BaEuZnSb ( = 0.02(1), 0.04(1), 0.
View Article and Find Full Text PDFAchieving Ultralow Lattice Thermal Conductivity and High Thermoelectric Performance in BiTeSe Alloys via Introducing Organic & Inorganic Nanoparticles.
Small
January 2025
Key Lab of Photovoltaic and Energy Conservation Materials, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei, 230031, P. R. China.
N-type BiTeSe(BTS) is a state-of-the-art thermoelectric material owing to its excellent thermoelectric properties near room temperatures for commercial applications. However, its performance is restricted by its comparatively low figure of merit ZT. Here, it is shown that a 14% increase in power factor (PF) (at 300 K) can be reached through incorporation of inorganic GaAs nanoparticles due to enhanced thermopower originating from the energy-dependent carrier scattering.
View Article and Find Full Text PDFBroad-Temperature Optical Thermometry via Dual Sensitivity of Self-Trapped Excitons Lifetime and Higher-Order Phonon Anharmonicity in Lead-Free Perovskites.
Angew Chem Int Ed Engl
January 2025
DICP: Chinese Academy of Sciences Dalian Institute of Chemical Physics, State Key Laboratory of Molecular Reaction Dynamics and Dalian Coherent Light Source, CHINA.
Broad-temperature optical thermometry necessitates materials with exceptional sensitivity and stability across varied thermal conditions, presenting challenges for conventional systems. Here, we report a lead-free, vacancy-ordered perovskite Cs2TeCl6, that achieves precise temperature sensing through a novel combination of self-trapped excitons (STEs) photoluminescence (PL) lifetime modulation and unprecedented fifth-order phonon anharmonicity. The STEs PL lifetime demonstrates a highly temperature-sensitive response from 200 to 300 K, ideal for low-to-intermediate thermal sensing.
View Article and Find Full Text PDFFirst-principles study of structural, elastic, electronic, transport properties, and dielectric breakdown of CsTe photocathode.
Sci Rep
January 2025
Accelerator Operations and Technology Division, Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM, 87545, USA.
The pursuit to operate photocathodes at high accelerating gradients to increase brightness of electron beams is gaining interests within the accelerator community, particularly for applications such as free electron lasers (FEL) and compact accelerators. Cesium telluride (CsTe) is a widely used photocathode material and it is presumed to offer resilience to higher gradients because of its wider band gap compared to other semiconductors. Despite its advantages, crucial material properties of CsTe remain largely unknown both in theory and experiments.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!