物理学の限界を目指す / Physics Frontier — 物理学ニュース https://physicsdiscussion.com/ 物理学の最新ニュースと査読論文の解説を、一次ソース（DOI・arXiv・機関発表）付きで日本語と英語で発信。Bilingual physics news with primary sources. ja Tue, 07 Jul 2026 00:00:00 +0900 Ultrafast scanning tunneling microscopy reaches the quantum-mechanical space-time limit for the first time: attosecond light pulses clock single-electron tunnelling from an atomically sharp tip to a silver surface, revealing a ~500-attosecond lag behind the light field and a trade-off between temporal localization and spatial spreading of electron wave packets (Maier, Repp, Huber, Giessibl, Richter, Rubio et al., University of Regensburg RUN / MPSD Hamburg, Nature Photonics) / アト秒光パルス×走査トンネル顕微鏡が量子力学の「時空限界」に初到達——探針から銀表面への単一電子トンネルをアト秒・原子分解能で追跡し、光の場に対する約500アト秒の遅れと、時間的局在と空間的広がりのトレードオフを解明（Maier・Repp・Huber・Giessibl・Richter・Rubioら、レーゲンスブルク大学RUN／マックス・プランク物質構造動力学研究所、Nature Photonics） https://physicsdiscussion.com/news-2026-07.html#n-20260706-1 https://physicsdiscussion.com/news-2026-07.html#n-20260706-1 Mon, 06 Jul 2026 00:00:00 +0900 First-ever quadsqueezing: combining two non-commuting spin-dependent forces on a single trapped ion generates second-, third- and fourth-order squeezing interactions over 100 times faster than conventional methods, with no fundamental limit on the interaction order (Bazavan, Saner, Webb, Srinivas et al., University of Oxford, Nature Physics) / 世界初の「クアッドスクイージング（4次スクイージング）」——単一トラップイオンに2つの非可換なスピン依存の力を組み合わせ、2次・3次・4次のスクイージング相互作用を従来の100倍以上高速に生成。相互作用の次数に原理的上限なし（Băzăvan・Saner・Webb・Srinivasら、オックスフォード大学、Nature Physics） https://physicsdiscussion.com/news-2026-07.html#n-20260706-2 https://physicsdiscussion.com/news-2026-07.html#n-20260706-2 Mon, 06 Jul 2026 00:00:00 +0900 The relativity of spacetime superpositions: superposed spacetimes that differ only by a coordinate transformation are equivalent to quantum dynamics on a single classical background, exposing an ambiguity in proposed quantum-gravity tests and clarifying what evidence would genuinely prove gravity is quantum (Foo, Suryaatmadja, Mann & Zych, Kyushu University IAS / University of Queensland / Waterloo & Perimeter Institute / Stockholm University, npj Quantum Information) / 「時空重ね合わせの相対性」——座標変換だけで結ばれる時空の重ね合わせは単一の古典時空上の量子ダイナミクスと等価であることを証明し、量子重力検証実験の解釈に潜む曖昧さと、真に量子重力を証明する条件を明確化（Foo〈九州大学高等研究院〉・Suryaatmadja・Mann・Zych、npj Quantum Information） https://physicsdiscussion.com/news-2026-07.html#n-20260706-3 https://physicsdiscussion.com/news-2026-07.html#n-20260706-3 Mon, 06 Jul 2026 00:00:00 +0900 Re-entrant superconductivity is observed at a two-dimensional oxide heterointerface: a magnetic field first destroys superconductivity in the ultrathin conducting layer between two insulating oxides, then unexpectedly revives it at higher fields, providing a precisely controllable platform for unconventional superconductivity (Maryenko et al., RIKEN Center for Emergent Matter Science, Science Advances) / 酸化物界面の極薄伝導層で「再突入（リエントラント）超伝導」を観測——磁場で一度消えた超伝導がより強い磁場で予想外に復活。精密制御可能な2次元プラットフォームで非従来型超伝導の量子機構に迫る（Maryenkoら、理研・創発物性科学研究センターCEMS、Science Advances） https://physicsdiscussion.com/news-2026-07.html#n-20260706-4 https://physicsdiscussion.com/news-2026-07.html#n-20260706-4 Mon, 06 Jul 2026 00:00:00 +0900 Classical discrete space-time crystals of Majorana-like quasiparticles are realized in chiral liquid crystals under Floquet electrical driving, with period doubling arising from inter-transforming topological solitons and disclinations, opening the field of time liquid crystallinity (Zhao, Zhang & Smalyukh, Hiroshima University WPI-SKCM2 / University of Colorado Boulder, Nature Communications) / フロケ電気駆動したキラル液晶で、マヨラナ的準粒子からなる古典的な離散時空結晶を実現——トポロジカルソリトンと転傾線の相互変換が周期倍化を生み、「時間液晶性」という新分野を開く（Zhao・Zhang・Smalyukh、広島大学WPI-SKCM²／コロラド大学ボルダー校、Nature Communications） https://physicsdiscussion.com/news-2026-07.html#n-20260706-5 https://physicsdiscussion.com/news-2026-07.html#n-20260706-5 Mon, 06 Jul 2026 00:00:00 +0900 All-optical writing and read-out of antiferromagnetic domains via an inverse optical magnetoelectric effect: ultrashort laser pulses, using the light's propagation direction rather than its polarization, switch and non-volatilely store magnetic information at telecom wavelengths without currents or magnetic fields (Kezsmarki et al., University of Augsburg and German-Japanese collaborators, Nature Materials) / 逆光学磁気電気効果により、光だけで反強磁性ドメインを書き込み・読み出し——偏光ではなく光の伝播方向を使い、電流も磁場も用いずに磁気情報を通信波長帯でスイッチし不揮発に保存（Kézsmárkiら、アウクスブルク大学ほか日独チーム、Nature Materials） https://physicsdiscussion.com/news-2026-07.html#n-20260706-6 https://physicsdiscussion.com/news-2026-07.html#n-20260706-6 Mon, 06 Jul 2026 00:00:00 +0900 A plug-and-play single-photon source that works at room temperature: gallium-nitride defect emitters with deterministic spatial mapping and circular Bragg gratings are packaged into a 19-inch rack-mounted device compatible with quantum key distribution equipment (KRISS / Kongju National University, Laser & Photonics Reviews) / 電源を入れるだけで動く室温単一光子源——GaN欠陥発光体を決定論的空間マッピングと円形ブラッグ回折格子で19インチラック装置化し、量子鍵配送（QKD）装置と接続可能に（KRISS／公州大学校、Laser & Photonics Reviews） https://physicsdiscussion.com/news-2026-07.html#n-20260706-7 https://physicsdiscussion.com/news-2026-07.html#n-20260706-7 Mon, 06 Jul 2026 00:00:00 +0900 Multi-wavelength observations reveal that the tidal disruption event AT 2018cqh in a dwarf galaxy was caused by an intermediate-mass black hole of about (1-6)x10^5 solar masses, with an X-ray rise lasting at least 550 days and an ongoing high-state plateau (Wang, Xue, Jiang et al., University of Science and Technology of China, Nature Communications) / 矮小銀河の潮汐破壊イベントAT 2018cqhが太陽の約10万〜60万倍の中間質量ブラックホールによるものと判明——550日超のX線増光と現在も続く高輝度プラトー相を発見（Wang・Xue・Jiangら、中国科学技術大学、Nature Communications） https://physicsdiscussion.com/news-2026-07.html#n-20260706-8 https://physicsdiscussion.com/news-2026-07.html#n-20260706-8 Mon, 06 Jul 2026 00:00:00 +0900 Efficient and stable saturated-blue perovskite LEDs are achieved by constructing hydrogen-bonding networks with isomeric molecules within the perovskite and at its interfaces, reaching external quantum efficiencies of 16.8% at 463 nm and 22.0% at 468 nm with markedly improved stability (Wang, Zhang, Yang et al., Shanghai University, Nature) / 異性体分子による多重水素結合ネットワークで、効率的で安定な純青色ペロブスカイトLEDを実現——外部量子効率は463nmで16.8%、468nmで22.0%に達し安定性も大幅向上（Wang・Zhang・Yangら、上海大学、Nature） https://physicsdiscussion.com/news-2026-07.html#n-20260706-9 https://physicsdiscussion.com/news-2026-07.html#n-20260706-9 Mon, 06 Jul 2026 00:00:00 +0900 A fully spin-polarised nu=1 integer quantum Hall state is demonstrated in a germanium quantum well at magnetic fields as low as ~0.25 tesla and comparatively high temperatures, enabled by ultra-dilute carriers and a large Zeeman energy on a CMOS-compatible chip (Myronov, Jiang, Studenikin et al., University of Warwick / National Research Council Canada, Communications Materials) / ゲルマニウム量子井戸で完全スピン偏極したν=1量子ホール状態を約0.25テスラの弱磁場・比較的高温で実現——極希薄キャリアと大きなゼーマンエネルギーを用いCMOS適合チップで実証（Myronov・Jiang・Studenikinら、ウォリック大学／カナダ国立研究機構、Communications Materials） https://physicsdiscussion.com/news-2026-07.html#n-20260706-10 https://physicsdiscussion.com/news-2026-07.html#n-20260706-10 Mon, 06 Jul 2026 00:00:00 +0900 Multi-wavelength JWST, Hubble and VLT observations of the starless ~3,200-light-year cavity at the center of the brightest cluster galaxy A402-BCG rule out dust and instead point to an ultramassive black-hole binary totaling about 60 billion solar masses spiraling together and ejecting stars (McDonald et al., MIT, Astrophysical Journal Letters) / 巨大楕円銀河A402-BCG中心の差し渡し約3200光年の星のない空洞をJWST・ハッブル・VLTで精査しダスト説を否定——合計で太陽の約600億倍の超大質量ブラックホール連星が渦を巻き星を弾き飛ばした可能性を提示（McDonaldら、マサチューセッツ工科大学、Astrophysical Journal Letters） https://physicsdiscussion.com/news-2026-07.html#n-20260706-11 https://physicsdiscussion.com/news-2026-07.html#n-20260706-11 Mon, 06 Jul 2026 00:00:00 +0900 Spectroscopy of the 2^3S1 -> 2^1S0 transition in helium-4 at 48 Hz (0.25 ppt) uncertainty using a Bose-Einstein condensate in a magic-wavelength trap yields the most precise squared charge-radius difference between the alpha particle and helion, r_h^2 - r_alpha^2 = 1.0676(10) fm^2, confirming the QED-ionization discrepancy does not appear in the isotope shift (Steinebach, Eikema et al., Vrije Universiteit Amsterdam, Physical Review Letters) / ボース・アインシュタイン凝縮したヘリウム4の2^3S1→2^1S0遷移を48ヘルツ（0.25 ppt）精度で分光し、α粒子とヘリオンの電荷半径2乗差を過去最高精度r_h^2-r_alpha^2=1.0676(10) fm^2で決定——ヘリウムのQED理論と実験の食い違いが同位体シフトには現れないことを確認（Steinebach・Eikemaら、アムステルダム自由大学、Phys. Rev. Lett.） https://physicsdiscussion.com/news-2026-07.html#n-20260706-12 https://physicsdiscussion.com/news-2026-07.html#n-20260706-12 Mon, 06 Jul 2026 00:00:00 +0900 Tracking 17 pieces of space debris aloft since the 1960s across three solar cycles (1986-2024) reveals a clear threshold: once the sunspot number exceeds about 67% of its cycle maximum, debris crosses a transition boundary and falls much faster, with the threshold tied to proximity to peak solar activity rather than an absolute radiation level (Ashruf et al., Vikram Sarabhai Space Centre, Frontiers in Astronomy and Space Sciences) / 1960年代打ち上げの17個の宇宙デブリを3つの太陽周期（1986-2024）にわたり追跡し、黒点数が最大値の約67%を超えるとデブリが遷移境界を越え急速に落下し始める閾値を発見——閾値は放射の絶対値でなく太陽活動ピークへの近さで決まる（Ashrufら、ヴィクラム・サラバイ宇宙センター、Frontiers in Astronomy and Space Sciences） https://physicsdiscussion.com/news-2026-07.html#n-20260706-13 https://physicsdiscussion.com/news-2026-07.html#n-20260706-13 Mon, 06 Jul 2026 00:00:00 +0900 Sixteen previously proposed structural descriptors for supercooled water are objectively evaluated within a unified framework built around a neural network that classifies temperature from molecular configurations, with explainable AI identifying the structural features driving predictions and establishing a data-driven benchmark for characterizing water's microscopic structure (Yoshikawa, Shikata, Kim, Matubayasi, University of Osaka, Communications Chemistry) / 過冷却水の16個の構造記述子を、分子配置から温度を分類するニューラルネットワークを軸にした統一枠組みで客観評価し、説明可能AIで判断根拠の構造特徴を特定——液体の水の構造指標をデータ駆動でベンチマークする枠組みを確立（吉川・四方・金・松林、大阪大学、Communications Chemistry） https://physicsdiscussion.com/news-2026-07.html#n-20260706-14 https://physicsdiscussion.com/news-2026-07.html#n-20260706-14 Mon, 06 Jul 2026 00:00:00 +0900 A student-built diamond quantum magnetometer using nitrogen-vacancy centers (OSCAR-QUBE) operated for about 10 months (2021-2022) inside the International Space Station, returning vector geomagnetic measurements matching the World Magnetic Model in a 1U, 420 g, 5 W package; framed as a proof of concept, its in-orbit precision was limited by onboard electromagnetic interference and did not surpass state-of-the-art magnetometers, but it validated survivability toward small-satellite geomagnetic mapping (Beerden, Hruby et al., Hasselt University / imec, Physical Review Applied) / 学生開発のダイヤモンド量子磁力計OSCAR-QUBE（NV中心利用・1U・420g・5W）が国際宇宙ステーション内で約10か月（2021〜2022年）動作し、地球磁場のベクトル測定が世界磁気モデルと一致することを概念実証——ISS内部設置ゆえ電磁干渉が精度の下限を決め従来最先端は超えないが、宇宙環境での動作持続を実証し小型衛星による地磁気マッピングへ道（Beerden・Hrubyら、ハッセルト大学／imec、Physical Review Applied） https://physicsdiscussion.com/news-2026-07.html#n-20260706-15 https://physicsdiscussion.com/news-2026-07.html#n-20260706-15 Mon, 06 Jul 2026 00:00:00 +0900 Flat-band superconductivity in alternating twisted quadrilayer graphene shows electric-field-tunable coupling strength, a maximum BKT transition temperature of 1.6 K, critical magnetic fields beyond the Pauli limit and a large superfluid stiffness despite vanishing Fermi velocity, attributed to quantum metric hot spots created by Dirac-flat band hybridization (Le Liu, K. T. Law, Guangyu Zhang, Wei Yang et al., Institute of Physics CAS / HKUST / NIMS, npj Quantum Materials, open access 4 July 2026; arXiv:2501.06460) / 交互ツイスト4層グラフェンの平坦バンド超伝導で、電場可変の結合強度・最大1.6KのBKT転移温度・パウリ限界超えの臨界磁場・フェルミ速度がほぼ消えても大きな超流動剛性を観測——ディラックバンドと平坦バンドの混成が生む量子計量ホットスポットに帰着（Le Liu・K. T. Law・Guangyu Zhang・Wei Yangら、中国科学院物理研究所／香港科技大／NIMS、npj Quantum Materials 2026年7月4日オープンアクセス掲載、arXiv:2501.06460） https://physicsdiscussion.com/news-2026-07.html#n-20260705-1 https://physicsdiscussion.com/news-2026-07.html#n-20260705-1 Sun, 05 Jul 2026 00:00:00 +0900 Quantum Gibbs samplers are proven to thermalize to the Gibbs state in polynomial time at high enough temperature for any Hamiltonian obeying a Lieb-Robinson bound, to prepare thermofield double states efficiently, and to be computationally equivalent to universal polynomial-time quantum computation at low temperature, establishing a rigorous quantum analogue of classical Monte Carlo (Rouzé, Stilck França & Alhambra, Inria-Télécom Paris / ENS de Lyon / IFT UAM-CSIC, Nature Physics, DOI: 10.1038/s41567-026-03246-y; News & Views early July 2026) / 散逸型の量子ギブスサンプラーが、十分高温ならリーブ・ロビンソン束縛を満たす任意のハミルトニアンで多項式時間のうちにギブス状態（熱平衡状態）へ到達し、熱場二重状態も効率的に準備でき、低温側では万能量子計算と計算論的に等価になることを証明——古典モンテカルロ法の厳密な量子版を確立（Rouzé・Stilck França・Alhambra、Inria／ENSリヨン／マドリード自治大IFT、Nature Physics掲載、DOI: 10.1038/s41567-026-03246-y、2026年7月初旬のNews & Viewsで解説） https://physicsdiscussion.com/news-2026-07.html#n-20260705-2 https://physicsdiscussion.com/news-2026-07.html#n-20260705-2 Sun, 05 Jul 2026 00:00:00 +0900 Quantum control protocols that stretch, blur or invert the arrow of time in monitored quantum systems are constructed: a feedback Hamiltonian can cancel, amplify or overcompensate measurement disturbances, simulate backward-in-time open dynamics, and power a continuous measurement engine from the energy injected by monitoring (García-Pintos, Liu & Gorshkov, Los Alamos National Laboratory / NIST / University of Maryland, Phys. Rev. X 16, 011028, DOI: 10.1103/l18s-9vmh) / 監視下の量子系の時間の矢を伸ばし・ぼかし・反転させる制御プロトコルを構築——フィードバック・ハミルトニアンで測定の擾乱を打ち消し・増幅・過補償し、開放量子系の時間逆行ダイナミクスを模擬し、測定が注ぎ込むエネルギーで動く連続測定エンジンを設計（García-Pintos・Liu・Gorshkov、ロスアラモス国立研究所／NIST／メリーランド大、Phys. Rev. X 16, 011028、DOI: 10.1103/l18s-9vmh） https://physicsdiscussion.com/news-2026-07.html#n-20260705-3 https://physicsdiscussion.com/news-2026-07.html#n-20260705-3 Sun, 05 Jul 2026 00:00:00 +0900 Supersonic electrons in an ultrahigh-mobility two-dimensional electron gas resonantly emit acoustic phonons: above the sound barrier (drift velocity ~3 km/s at ~1.1 A/m) strong phonon-induced resistance oscillations persist from 3.9 K down to 10 mK, exceeding existing theory and pointing toward controllable on-chip phonon sources and phonon lasers (Z. T. Wang, M. Hilke et al., McGill University / NRC Canada / Princeton, Phys. Rev. Lett. 136, 146302, DOI: 10.1103/m1nb-j1h6) / 超高移動度の二次元電子系で音速を超えた電子がフォノンを共鳴放出——ドリフト速度が音速（約3km/s、電流密度約1.1A/m）を超えると、3.9Kから10mKまで強いフォノン誘起抵抗振動が持続し、既存理論の予測を上回る。チップ上の制御可能なフォノン源・フォノンレーザーへの道（Z. T. Wang・M. Hilkeら、マギル大／カナダ国立研究機構／プリンストン大、Phys. Rev. Lett. 136, 146302、DOI: 10.1103/m1nb-j1h6） https://physicsdiscussion.com/news-2026-07.html#n-20260705-4 https://physicsdiscussion.com/news-2026-07.html#n-20260705-4 Sun, 05 Jul 2026 00:00:00 +0900 First controlled molecular rotation inside a superfluid: a modified optical centrifuge with a short pulse delay spins nitric-oxide dimers in helium nanodroplets with directly tunable direction and frequency, opening the study of how superfluidity breaks down at the atomic scale (MacPhail-Bartley, A. A. Milner, Stienkemeier & V. Milner, University of British Columbia / University of Freiburg, Phys. Rev. Lett. 136, 033002, DOI: 10.1103/5jnj-97vs) / 超流動体の中で分子の回転を初めて制御——パルス間に短い遅延を入れた改良型光学遠心機で、ヘリウムナノ液滴中の一酸化窒素二量体の回転方向と回転数を直接調整。超流動が原子スケールで壊れる仕組みの研究に道（MacPhail-Bartley・A. A. Milner・Stienkemeier・V. Milner、ブリティッシュコロンビア大／フライブルク大、Phys. Rev. Lett. 136, 033002、DOI: 10.1103/5jnj-97vs） https://physicsdiscussion.com/news-2026-07.html#n-20260705-5 https://physicsdiscussion.com/news-2026-07.html#n-20260705-5 Sun, 05 Jul 2026 00:00:00 +0900