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1. Ultra-narrow TaS2 nanoribbon

   Cain, J. D.; Oh, S.; Azizi, A.; Stonemeyer, S.; Dogan, M.; Thiel, M.; Ercius, P.; Cohen, M. L.; Zettl, A. (January 2021, Nano letters)
2. Ultra-narrow TaS2 nanoribbon

   Dogan, M.; Cohen, M. L. (January 2021, Nano letters)
3. Understanding the Radio Spectrum of Thunderstorm Narrow Bipolar Events

   https://doi.org/10.1029/2019JD030439  

   Liu, Ningyu; Dwyer, Joseph R.; Tilles, Julia N.; Stanley, Mark A.; Krehbiel, Paul R.; Rison, William; Brown, Robert G.; Wilson, Jennifer G. (September 2019, Journal of Geophysical Research: Atmospheres)

   Abstract This paper reports a study to understand the radio spectrum of thunderstorm narrow bipolar events (NBEs) or compact intracloud discharges, which are powerful sources of high‐frequency (HF) and very high frequency (VHF) electromagnetic radiation. The radio spectra from 10 kHz to about 100 MHz are obtained for three NBEs, including one caused by fast positive breakdown and two by fast negative breakdown. The results indicate that the two polarities of fast breakdown have similar spectra, with a relatively flat spectrum in the HF and VHF band. The ratio of energy spectral densities in the very low frequency and HF bands is (0.9–5) × 10⁵. We develop a statistical modeling approach to investigate if a system of streamers can explain the main features of fast breakdown. Assuming that the current moment peak and charge moment change of individual streamers vary in the ranges of 5–10 A‐m and 5–20 μC‐m, respectively, the modeling results indicate that a system of 10⁷–10⁸streamers can reproduce the current moment, charge transfer, and radio spectrum of fast breakdown. The rapid current variation on a time scale of nanoseconds required for fast breakdown to produce strong HF/VHF emissions is provided by exponentially accelerating and expanding streamers. Our study therefore supports the hypothesis that fast breakdown is a system of streamers. Finally, suggestions are given regarding future streamer simulations and NBE measurements in order to further develop our understanding of NBEs and lightning initiation. 

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4. Narrow-linewidth exciton-polariton laser

   https://doi.org/10.1364/OPTICA.525961  

   Fabricante, Bianca Rae; Król, Mateusz; Wurdack, Matthias; Pieczarka, Maciej; Steger, Mark; Snoke, David W; West, Kenneth; Pfeiffer, Loren N; Truscott, Andrew G; Ostrovskaya, Elena A; et al (January 2024, Optica)

   Exciton-polariton lasers are a promising source of coherent light for low-energy applications due to their low-threshold operation. However, a detailed experimental study of their spectral purity, which directly affects their coherence properties, is still missing. Here, we present a high-resolution spectroscopic investigation of the energy and linewidth of an exciton-polariton laser in the single-mode regime, which derives its coherent emission from an optically pumped and confined exciton-polariton condensate. We report an ultra-narrow linewidth of 56 MHz or 0.24 µeV, corresponding to a coherence time of 5.7 ns. The narrow linewidth is consistently achieved by using an exciton-polariton condensate with a high photonic content confined in an optically induced trap. Contrary to previous studies, we show that the excitonic reservoir created by the pump and responsible for creating the trap does not strongly affect the emission linewidth as long as the condensate is trapped and the pump power is well above the condensation (lasing) threshold. The long coherence time of the exciton-polariton system uncovered here opens up opportunities for manipulating its macroscopic quantum state, which is essential for applications in classical and quantum computing. 

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5. Narrow escape with imperfect reactions

   https://doi.org/10.1103/PhysRevE.110.054127  

   Cengiz, Anıl; Lawley, Sean D (November 2024, Physical Review E)