未知なる宇宙の物質探査を進める量子検出器（We Have No Idea What Most of the Universe Is Made Of, but Scientists Are Closer Than Ever to Finding Out）

2026-01-06 テキサスA&M大学

Dr. Rupak Mahapatra, an experimental particle physicist, holds a TESSERACT detector. The highly sensitive devices, which are fabricated at Texas A&M University, are deepening the search for dark matter and have potential applications in quantum computing.Credit: Laura McKenzie/Texas A&M University Division of Marketing and Communications

＜関連情報＞

• https://stories.tamu.edu/news/2026/01/06/we-have-no-idea-what-most-of-the-universe-is-made-of-but-scientists-are-closer-than-ever-to-finding-out/
• https://pubs.aip.org/aip/apl/article-abstract/127/26/263502/3375826/Spontaneous-generation-of-athermal-phonon-bursts
• https://arxiv.org/abs/2210.05380
• https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.112.041302

バルクシリコン内での無熱フォノンバーストの自発的発生により、過剰なノイズ、低エネルギー背景イベント、超伝導センサーにおける準粒子中毒が発生する Spontaneous generation of athermal phonon bursts within bulk silicon causing excess noise, low energy background events, and quasiparticle poisoning in superconducting sensors

C. L. Chang;Y.-Y. Chang;M. Garcia-Sciveres;W. Guo;S. A. Hertel;X. Li;J. Lin;M. Lisovenko;R. Mahapatra;W. Matava;D. N. McKinsey;P. K. Patel;B. Penning;H. D. Pinckney;M. Platt;M. Pyle;Y. Qi;M. Reed;I. Rydstrom;R. K. RomaniCorresponding Author;B. Sadoulet;B. Serfass;P. Sorensen;B. Suerfu;V. Velan;G. Wang;Y. Wang;M. R. Williams;V. G. Yefremenko;TESSERACT Collaboration
Applied Physics Letters  Published:December 30 2025
DOI:https://doi.org/10.1063/5.0281876

Solid state phonon detectors used in the search for dark matter and coherent neutrino nucleus interactions (CE v NS) require excellent energy resolution (eV-scale or below) and low backgrounds. An unknown source of phonon bursts, the low energy excess (LEE), dominates other above-threshold backgrounds and generates excess shot noise from subthreshold bursts. In this paper, we measure these phonon bursts for 12 days after cooldown in two nearly identical 1 cm² silicon detectors that differ only in the thickness of their substrate (1 vs 4 mm thick). We find that both the channel-correlated shot noise and near-threshold shared LEE relax with time since cooldown. Additionally, both the correlated shot noise and LEE rates scale linearly with substrate thickness. When combined with previous measurements of other silicon phonon detectors with different substrate geometries and mechanical support strategies, these measurements strongly suggest that the dominant source of both above and below threshold LEE is the bulk substrate. By monitoring the relation between bias power and excess phonon shot noise, we estimate that the energy scale for subthreshold noise events is 0.68± 0.38 meV. In our final dataset, we report a world-leading energy resolution of 258.5± 0.4 meV in the 1 mm thick detector. Simple calculations suggest that these silicon substrate phonon bursts are likely a significant source of quasiparticle poisoning in superconducting qubits operated in well shielded and vibration free environments.

70 GeV暗黒物質WIMPの間接検出、直接検出、衝突型検出断面積 Indirect detection, direct detection, and collider detection cross-sections for a 70 GeV dark matter WIMP

Bailey Tallman, Alexandra Boone, Caden LaFontaine, Trevor Croteau, Quinn Ballard, Sabrina Hernandez, Spencer Ellis, Adhithya Vijayakumarm, Fiona Lopez, Samuel Apata, Jehu Martinez, Roland Allen
arXiv  Submitted on 8 Oct 2022
DOI:https://doi.org/10.48550/arXiv.2210.05380

Abstract

Assuming a dark matter fraction Ω = 0.27 and a reduced Hubble constant ℎ = 0.73, we obtain a value of 70 GeV/c² for the mass of the dark matter WIMP we have previously proposed. We also obtain a value for the annihilation cross section given by () = 1.19 × 10⁻²⁶ cm³ /s in the present universe, consistent with the current limits for dwarf spheroidal galaxies. Both the mass and cross-section are consistent with analyses of the Galactic-center gamma rays observed by Fermi-LAT and the antiprotons observed by AMS-02 if these data are interpreted as resulting from dark matter annihilation. The spin-independent cross-section for direct detection in Xe-based experiments is estimated to be slightly above 10⁻⁴⁸ cm² , presumably just within reach of the LZ and XENONnT experiments with & 1000 days of data taking. The cross-section for production in high-energy proton collisions via vector boson fusion is estimated to be ∼ 1 femtobarn, possibly within reach of the high-luminosity LHC, with ≥ 140 GeV of missing energy accompanied by two jets.

SuperCDMS実験における電圧支援熱量測定イオン化検出を用いた低質量で弱い相互作用をする巨大粒子の探索 Search for Low-Mass Weakly Interacting Massive Particles Using Voltage-Assisted Calorimetric Ionization Detection in the SuperCDMS Experiment

R. Agnese, A. J. Anderson, M. Asai, D. Balakishiyeva, R. Basu Thakur, D. A. Bauer, J. Billard, A. Borgland, M. A. Bowles et al. (SuperCDMS collaboration)
Physical Review Letters  Published 27 January, 2014
DOI: https://doi.org/10.1103/PhysRevLett.112.041302

Abstract

SuperCDMS is an experiment designed to directly detect weakly interacting massive particles (WIMPs), a favored candidate for dark matter ubiquitous in the Universe. In this Letter, we present WIMP-search results using a calorimetric technique we call CDMSlite, which relies on voltage-assisted Luke-Neganov amplification of the ionization energy deposited by particle interactions. The data were collected with a single 0.6 kg germanium detector running for ten live days at the Soudan Underground Laboratory. A low energy threshold of 170  eV_ee (electron equivalent) was obtained, which allows us to constrain new WIMP-nucleon spin-independent parameter space for WIMP masses below 6  GeV/².