We measure the current fluctuations emitted by a normal-metal-insulator-normal-metal tunnel junction with a very wide bandwidth, from 0.3 to 13 GHz, down to very low temperature T=35 mK. This allows us to perform the spectroscopy (i.e., measure the frequency dependence) of thermal noise (no dc bias, variable temperature) and shot noise (low temperature, variable dc voltage bias). Because of the very wide bandwidth of our measurement, we deduce the current-current correlator in the time domain. We observe the thermal decay of this correlator as well as its oscillations with a period h/eV, a direct consequence of the effect of the Pauli and Heisenberg principles in quantum electron transport.
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http://dx.doi.org/10.1103/PhysRevLett.114.236604 | DOI Listing |
Adv Mater
January 2025
Institute of Materials Physics, University of Münster, Wilhelm-Klemm-Str. 10, 48149, Münster, Germany.
As a phase change material (PCM), antimony exhibits a set of desirable properties that make it an interesting candidate for photonic memory applications. These include a large optical contrast between crystalline and amorphous solid states over a wide wavelength range. Switching between the states is possible on nanosecond timescales by applying short heating pulses.
View Article and Find Full Text PDFSensors (Basel)
January 2025
Department of Electronics and Communication Engineering, SRM University, Guntur 522240, Andhra Pradesh, India.
We propose herein a metamaterial (MM) dual-band THz sensor for various biomedical sensing applications. An MM is a material engineered to have a particular property that is rarely observed in naturally occurring materials with an aperiodic subwavelength arrangement. MM properties across a wide range of frequencies, like high sensitivity and quality factors, remain challenging to obtain.
View Article and Find Full Text PDFPolymers (Basel)
December 2024
Key Laboratory of Bamboo Research of Zhejiang Province, Zhejiang Academy of Forestry, Hangzhou 310023, China.
Bamboo was carbonized and further modified via co-doping with graphene oxide (GO) and polyaniline (PANI) to prepare microwave absorption composites (GO/PANI/CB) by in situ polymerization of 1R-(-)-Camphorsulfonic acid (L-CSA). The conductivity of GO/PANI/CB reached 2.17 ± 0.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Tsinghua University, Chemistry, HeTian Building Dept. of Chemistry, Tsinghua University, Beijing, P. R. China, 100084, Beijing, CHINA.
Expanded heterohelicene composing of alternating linearly and angularly fused multi-resonance (MR) skeleton has garnered wide interest for their promising narrowband emission. Herein, a pair of sym- and asym-expanded heterohelicene isomers are firstly developed by merging boron/oxygen (B/O)-embedded MR triangulene and indolo[3,2,1-jk]carbazole units via one-shot synthesis. Owing to the fully resonating extended helical skeleton, the target heterohelicenes exhibit significantly narrowed spectra bandwidth while emission red-shifting, thus affording deep-blue narrowband emission with peak at around 460 nm, full-width-at-half-maximum (FWHM) of merely 18 nm and near-unity photoluminescence quantum yields.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China.
Presently, researchers are placing emphasis on microwave absorption coating design while neglecting the research on materials that integrate both microwave absorption performance and mechanical properties. Here, robust FeSiAl/PEEK composites were prepared by a series process, including post ball-milling annealing, sol-gel method, and hot pressing. A detailed analysis of the electromagnetic (EM) parameters reveals the significant effects of morphology, filling ratio, and microstructure of FeSiAl on EM losses under a wide-temperature range.
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