Nature Physics最新文献_第4页

Plasticky ice

IF 19.6 1区物理与天体物理

Nature Physics Pub Date : 2025-04-11 DOI: 10.1038/s41567-025-02891-z

Debarchan Das

引用次数: 0

Continuous recoil-driven lasing and cavity frequency pinning with laser-cooled atoms 用激光冷却原子进行连续反冲驱动激光和腔频钉钉

IF 19.6 1区物理与天体物理

Nature Physics Pub Date : 2025-04-11 DOI: 10.1038/s41567-025-02854-4

Vera M. Schäfer, Zhijing Niu, Julia R. K. Cline, Dylan J. Young, Eric Yilun Song, Helmut Ritsch, James K. Thompson

{"title":"Continuous recoil-driven lasing and cavity frequency pinning with laser-cooled atoms","authors":"Vera M. Schäfer, Zhijing Niu, Julia R. K. Cline, Dylan J. Young, Eric Yilun Song, Helmut Ritsch, James K. Thompson","doi":"10.1038/s41567-025-02854-4","DOIUrl":"https://doi.org/10.1038/s41567-025-02854-4","url":null,"abstract":"Laser-cooled gases of atoms interacting with the field of an optical cavity are a versatile tool for quantum sensing and the simulation of quantum systems. These systems can exhibit phenomena such as self-organization phase transitions, lasing mechanisms, squeezed states and protection of quantum coherence. However, investigations of these phenomena typically occur in a discontinuous manner due to the need to reload atomic ensembles. Here we demonstrate hours-long continuous lasing from laser-cooled 88Sr atoms loaded into a ring cavity. The required inversion to produce lasing arises from inversion in the atomic-momentum degrees of freedom, which is linked to the self-organization phase transitions and collective atomic recoil lasing observed previously only in a cyclic fashion. We find that over a broad parameter range, the sensitivity of the lasing frequency to changes in cavity frequency is significantly reduced due to an atomic loss mechanism, suggesting a potential approach for mitigating low-frequency cavity noise. Our findings open opportunities for continuous cavity quantum electrodynamics experiments and robust and continuous super-radiant lasers.","PeriodicalId":19100,"journal":{"name":"Nature Physics","volume":"74 1","pages":""},"PeriodicalIF":19.6,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143819097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The past and present of frozen bubbles 冰冻气泡的过去和现在

IF 19.6 1区物理与天体物理

Nature Physics Pub Date : 2025-04-11 DOI: 10.1038/s41567-025-02892-y

Lishu Wu

{"title":"The past and present of frozen bubbles","authors":"Lishu Wu","doi":"10.1038/s41567-025-02892-y","DOIUrl":"https://doi.org/10.1038/s41567-025-02892-y","url":null,"abstract":"Previous studies invoked scaling laws or mechanisms such as heat transfer, phase change, capillarity, mass diffusion, and nucleation to explain the growth of ice bubbles. However, a comprehensive and quantitative model connecting bubble shapes to freezing conditions remained elusive. In particular, the interplay between freezing rates, gas diffusion, and capillary forces was poorly understood, limiting predictions and control of pore structures in ice and other freeze-cast materials.Thiévenaz and co-workers derived a single nonlinear ordinary differential equation to describe the growth and shapes of air bubbles trapped in ice during freezing. The equation depends on two nondimensional parameters. One is the supersaturation of the gas in the liquid — defined as the excess gas concentration with respect to the solubility over the density of air. The other is the ratio of the characteristic times of freezing and mass diffusion, describing the freezing velocity. The equation predicts that bubbles take on an elongated and asymmetric shape with a rounded tip. It also predicts a bifurcation when the supersaturation parameter is twice the freezing velocity, which explains how bubbles either close or grow indefinitely into ‘worm bubbles’.","PeriodicalId":19100,"journal":{"name":"Nature Physics","volume":"60 1","pages":""},"PeriodicalIF":19.6,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143822705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Underrepresentation of women last authors in Nature Physics 《自然物理学》杂志女性最后作者的代表性不足

IF 19.6 1区物理与天体物理

Nature Physics Pub Date : 2025-04-11 DOI: 10.1038/s41567-025-02857-1

Alannah M. Hallas

引用次数: 0

A closer look at authorship in Nature Physics 《自然物理》杂志作者身份的进一步研究

IF 19.6 1区物理与天体物理

Nature Physics Pub Date : 2025-04-11 DOI: 10.1038/s41567-025-02895-9

引用次数: 0

The key for interstellar travel might be light 星际旅行的关键可能是光

IF 19.6 1区物理与天体物理

Nature Physics Pub Date : 2025-04-11 DOI: 10.1038/s41567-025-02867-z

Mark Buchanan

{"title":"The key for interstellar travel might be light","authors":"Mark Buchanan","doi":"10.1038/s41567-025-02867-z","DOIUrl":"https://doi.org/10.1038/s41567-025-02867-z","url":null,"abstract":"The implication, then, is that we will need something that is not a rocket, that is, something propelled by an external energy source. One idea is a high-power laser driving a light sail of low mass with photon momentum. It sounds like science fiction, and serious estimates of the practical requirements illustrate a series of immense challenges. Even so, it may be possible. According to a recent analysis, radiation pressure generated by very large but realistic arrays of lasers could accelerate a reflective light-sail spacecraft to speeds as high as 0.2c. Such a craft could reach Proxima Centauri in about 20 years (J. Y. Lin et al. Preprint at https://doi.org/10.48550/arXiv.2502.17828; 2025).This is the idea behind the Breakthrough Foundation’s Starshot Initiative (https://breakthroughinitiatives.org/initiative/3), which aims to lay the groundwork for ultrafast, light-driven nanocrafts reaching the Alpha Centauri system (comprising Proxima Centauri and two other stars) within the next generation. The payload might be a small instrument able to carry out advanced imaging of the exoplanets surrounding the star, determining their habitability far more accurately than Earth-based measurements. The concept is straightforward; the challenges, as Lin and colleagues discuss, arise from a variety of practical needs — a lightweight and highly reflective sail to reach high speeds, efficient radiative cooling to protect against laser heating, and dynamical and structural stability to keep the craft intact and on course.","PeriodicalId":19100,"journal":{"name":"Nature Physics","volume":"75 1","pages":""},"PeriodicalIF":19.6,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143822706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Topological dynamics of rapid non-planar gaits in slithering snakes 蛇类快速非平面步态的拓扑动力学

IF 19.6 1区物理与天体物理

Nature Physics Pub Date : 2025-04-10 DOI: 10.1038/s41567-025-02835-7

N. Charles, R. Chelakkot, M. Gazzola, B. Young, L. Mahadevan

引用次数: 0

Resourceful dissipation 足智多谋的耗散

IF 19.6 1区物理与天体物理

Nature Physics Pub Date : 2025-04-08 DOI: 10.1038/s41567-025-02881-1

Yann Kiefer

引用次数: 0

Concurrent spin squeezing and field tracking with machine learning 同时旋转挤压和场跟踪与机器学习

IF 19.6 1区物理与天体物理

Nature Physics Pub Date : 2025-04-08 DOI: 10.1038/s41567-025-02855-3

Junlei Duan, Zhiwei Hu, Xingda Lu, Liantuan Xiao, Suotang Jia, Klaus Mølmer, Yanhong Xiao

{"title":"Concurrent spin squeezing and field tracking with machine learning","authors":"Junlei Duan, Zhiwei Hu, Xingda Lu, Liantuan Xiao, Suotang Jia, Klaus Mølmer, Yanhong Xiao","doi":"10.1038/s41567-025-02855-3","DOIUrl":"https://doi.org/10.1038/s41567-025-02855-3","url":null,"abstract":"Squeezing and entanglement play crucial roles in approaches for quantum metrology. Yet, demonstrating quantum enhancement in continuous signal tracking remains a challenging endeavour because simultaneous entanglement generation and signal perturbations are often incompatible. We demonstrate that concurrent steady-state spin squeezing and sensing are possible using continuous quantum non-demolition measurements under constant optical pumping. We achieve a sustained spin-squeezed state with a large ensemble of hot atoms using metrologically relevant steady-state squeezing. We further employ the system to track different types of continuous time-fluctuating magnetic fields, and we demonstrate the use of deep learning models to infer the time-varying fields from an optical measurement. The quantum enhancement due to spin squeezing was verified by a degraded performance in test experiments where the spin squeezing was deliberately prevented. These results represent an advance in continuous quantum-enhanced metrology with entangled atoms, including the training and application of a deep neural network to infer complex time-dependent perturbations.","PeriodicalId":19100,"journal":{"name":"Nature Physics","volume":"25 1","pages":""},"PeriodicalIF":19.6,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143797696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Bacterial second messengers achieve extraordinary signal capacity 细菌的第二信使具有非凡的信号能力

IF 19.6 1区物理与天体物理

Nature Physics Pub Date : 2025-04-08 DOI: 10.1038/s41567-025-02856-2

引用次数: 0