New Journal of Physics最新文献

Soliton sheets of Bose-Einstein condensates in optical lattices 光晶格中玻色-爱因斯坦凝聚体的孤子片

New Journal of Physics Pub Date : 2024-07-26 DOI: 10.1088/1367-2630/ad67ff

Shusong Wang, Suying Zhang

引用次数: 0

Novel Emergent Phases in a Two-Dimensional Superconductor 二维超导体中的新出现物相

New Journal of Physics Pub Date : 2024-07-26 DOI: 10.1088/1367-2630/ad6800

Simrandeep Kaur, Hemanta Kumar Kundu, Sumit Kumar, A. Dogra, R. Narayanan, T. Vojta, A. Bid

{"title":"Novel Emergent Phases in a Two-Dimensional Superconductor","authors":"Simrandeep Kaur, Hemanta Kumar Kundu, Sumit Kumar, A. Dogra, R. Narayanan, T. Vojta, A. Bid","doi":"10.1088/1367-2630/ad6800","DOIUrl":"https://doi.org/10.1088/1367-2630/ad6800","url":null,"abstract":"\u0000 In this letter, we report our observation of an extraordinarily rich phase diagram of a LaScO$_3$/SrTiO$_3$ heterostructure. Close to the superconducting transition temperature, the system hosts a superconducting critical point of the Infinite-randomness type characterized by an effective dynamical exponent $nu z$ that diverges logarithmically. At lower temperatures, we find the emergence of a magnetic field-tuned metallic phase that co-exists with a quantum Griffiths phase (QGP). Our study reveals a previously unobserved phenomenon in 2D superconductors -- an unanticipated suppression of the QGP below a crossover temperature in this system. This concealment is accompanied by the destruction of the superconducting quantum critical point signaled by a power-law divergence (in temperature) of the effective dynamical exponent. These observations are entirely at odds with the predictions of the infinite-randomness scenario and challenge the very concept of a vanishing energy scale associated with a quantum critical point. We develop and discuss possible scenarios like smearing of the phase transition that could plausibly explain our observations. Our findings challenge the notion that QGP is the ultimate ground state in two-dimensional superconductors.","PeriodicalId":508829,"journal":{"name":"New Journal of Physics","volume":"39 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141798751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Turbulence Closure Modeling with Machine Learning: A Foundational Physics Perspective 用机器学习进行湍流闭合建模：基础物理学视角

New Journal of Physics Pub Date : 2024-07-23 DOI: 10.1088/1367-2630/ad6689

S. Girimaji

{"title":"Turbulence Closure Modeling with Machine Learning: A Foundational Physics Perspective","authors":"S. Girimaji","doi":"10.1088/1367-2630/ad6689","DOIUrl":"https://doi.org/10.1088/1367-2630/ad6689","url":null,"abstract":"\u0000 Turbulence closure modeling using machine learning is at an early crossroads. The extraordinary success of machine learning (ML) in a variety of challenging fields had given rise to an expectation of similar transformative advances in the area of turbulence closure modeling. However, by most accounts, the current rate of progress toward accurate and predictive ML-RANS (Reynolds Averaged Navier-Stokes) closure models has been very slow. Upon retrospection, the absence of rapid transformative progress can be attributed to two factors: the underestimation of the intricacies of turbulence modeling and the overestimation of ML’s ability to capture all features without employing targeted strategies. To pave the way for more meaningful ML closures tailored to address the nuances of turbulence, this article seeks to review the foundational flow physics to assess the challenges in the context of data-driven approaches. Revisiting analogies with statistical mechanics and stochastic systems, the key physical complexities and mathematical limitations are explicated. It is noted that the current ML approaches do not systematically address the inherent limitations of a statistical approach or the inadequacies of the mathematical forms of closure expressions. The study underscores the drawbacks of supervised learning-based closures and stresses the importance of a more discerning ML modeling framework. As ML methods evolve (which is happening at a rapid pace) and our understanding of the turbulence phenomenon improves, the inferences expressed here should be suitably modified.","PeriodicalId":508829,"journal":{"name":"New Journal of Physics","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141810959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Flat Bands in Three-dimensional Lattice models with Non-trivial Hopf Index 具有非三维霍普夫指数的三维晶格模型中的平带

New Journal of Physics Pub Date : 2024-07-23 DOI: 10.1088/1367-2630/ad668a

Ivan Dutta, Kush Saha

{"title":"Flat Bands in Three-dimensional Lattice models with Non-trivial Hopf Index","authors":"Ivan Dutta, Kush Saha","doi":"10.1088/1367-2630/ad668a","DOIUrl":"https://doi.org/10.1088/1367-2630/ad668a","url":null,"abstract":"\u0000 We report the presence of exactly and nearly flat bands with non-trivial topology in three-dimensional (3D) lattice models. We first show that an exactly flat band can be realized in a 3D lattice model characterised by a 3D topological invariant, namely Hopf invariant. In contrast, we find another distinct 3D model, exhibiting both 2D Chern and 3D Hopf invariant, namely Hopf-Chern insulator, that can host nearly or perfect flat bands across different 2D planes. Such a Hopf-Chern model can be constructed by introducing specific hopping along the orthogonal direction of a simple two-orbital 2D Chern insulator in the presence of in-plane nearest-neighbor and next-nearest hopping among different orbitals. While the Chern planes host nearly perfect flat bands, the orthogonal planes can host both perfect or nearly perfect flat bands with zero Chern number at some special parameter values. Interestingly, such a 3D lattice construction from 2D allows finite Hopf invariant too. Finally, we show that higher Chern models can also be constructed in the same lattice setup with only nearest and next-nearest hopping, but the appearance of flat bands along high-symmetric path in the Brillouin zone requires longer-range hopping. We close with a discussion on possible experimental platforms to realize the models.","PeriodicalId":508829,"journal":{"name":"New Journal of Physics","volume":"102 24","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141812301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Long-lived, pulse-induced transient absorption inLiNb1-x Ta x O3 (0≤x≤1) solid solutions: the case of three intrinsic defect sites for electron localization with strong coupling LiNb1-x Ta x O3 (0≤x≤1)固溶体中的长寿命脉冲诱导瞬态吸收：强耦合电子局域化的三个本征缺陷位点的情况

New Journal of Physics Pub Date : 2024-07-23 DOI: 10.1088/1367-2630/ad6688

Niklas Dömer, Julian Koelmann, Mira Hesselink, Tobias Hehemann, Anton Pfannstiel, Felix Sauerwein, L. Vittadello, Steffen Ganschow, M. Imlau

{"title":"Long-lived, pulse-induced transient absorption inLiNb1-x\u0000 Ta\u0000 x\u0000 O3 (0≤x≤1) solid solutions: the case of three intrinsic defect sites for electron localization with strong coupling","authors":"Niklas Dömer, Julian Koelmann, Mira Hesselink, Tobias Hehemann, Anton Pfannstiel, Felix Sauerwein, L. Vittadello, Steffen Ganschow, M. Imlau","doi":"10.1088/1367-2630/ad6688","DOIUrl":"https://doi.org/10.1088/1367-2630/ad6688","url":null,"abstract":"\u0000 Femto-/nanosecond pulse-induced, red and near-infrared absorption is studied in LiNb1-x\u0000 Ta\u0000 x\u0000 O3 (0≤x≤1, LNT) solid solutions with the aim of studying transient optical nonlinearities associated with the formation, transport and recombination of optically generated small bound electron polarons with strong coupling to the lattice. As a result, a pronounced, long-lived transient absorption is uncovered for LNT which exceed lifetimes and starting amplitudes of LiNbO3 (LN) and LiTaO3 (LT) by a factor of up to 100 and 10, respectively. The transients reveal a stretched-exponential decay behavior and a thermally activated process which provide strong evidence for an underlying hopping transport mechanism of small bound polarons. All findings are discussed in comparison to the model systems LN and LT within the framework of appropriate band models and optical generation of polarons via two-photon excitation. To explain the significant differences, the simultaneous presence of Nb5+\u0000 Li , Ta5+\u0000 Li antisites, and Ta5+\u0000 V interstitial defects, i.e. a mixture of the intrinsic defects widely established for LN and LT, is assumed for LNT.","PeriodicalId":508829,"journal":{"name":"New Journal of Physics","volume":"88 21","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141812559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Antibunched Ν-photon bundles from dark states assisted by ac Stark shift 由交流斯塔克偏移辅助的暗态反束Ν光子束

New Journal of Physics Pub Date : 2024-07-22 DOI: 10.1088/1367-2630/ad6633

Chengdeng Gou, Jun Xu, Fei Wang, Xiangming Hu

引用次数: 0

Energy Stabilization of High-Charge Bunches from Laser Plasma Accelerators 激光等离子加速器高电荷束的能量稳定

New Journal of Physics Pub Date : 2024-07-22 DOI: 10.1088/1367-2630/ad6634

Xueyan Shi, Haisheng Xu, Dazhang Li, Jia Wang, Ming Zeng

引用次数: 0

Randomised benchmarking for universal qudit gates 通用量化门的随机基准测试

New Journal of Physics Pub Date : 2024-07-15 DOI: 10.1088/1367-2630/ad6635

David Amaro-Alcal'a, Barry C. Sanders, H. de Guise

引用次数: 1

Efficient and Reliable Detection of Nonlocal Quantum Correlations in Continuous-Variable and Hybrid States via Random Measurements 通过随机测量高效可靠地探测连续变量态和混合态中的非局部量子相关性

New Journal of Physics Pub Date : 2024-07-12 DOI: 10.1088/1367-2630/ad6283

Artur Barasinski, Nazarii Sudak, Jan Perina Jr

引用次数: 0

Spin-polarization and Coulomb interaction dependent thermal rectification in a quantum dot system 量子点系统中取决于自旋极化和库仑相互作用的热整流

New Journal of Physics Pub Date : 2024-07-09 DOI: 10.1088/1367-2630/ad60ef

Yufeng Su, Fenghua Qi, Guojun Jin

{"title":"Spin-polarization and Coulomb interaction dependent thermal rectification in a quantum dot system","authors":"Yufeng Su, Fenghua Qi, Guojun Jin","doi":"10.1088/1367-2630/ad60ef","DOIUrl":"https://doi.org/10.1088/1367-2630/ad60ef","url":null,"abstract":"\u0000 Based on the master equation approach, we investigate the thermal transport through a diode composed of a quantum dot under Coulomb interaction and tunnel-coupled to two ferromagnetic leads with antiparallel spin polarizations. We analyze the effects of spin polarizations, Coulomb interaction, mean temperature and Zeeman splitting on the thermal rectification. Firstly, we find that the thermal rectification effect is enhanced with the increase of spin polarization, because the mirror-symmetry of the system is broken by the anti-parallel spin polarization. Especially, when both leads are fully spin polarized, the asymmetry of the heat transferred by Coulomb interaction under the opposite temperature bias leads to the appearance of perfect thermal rectification and negative differential thermal conductance. Secondly, we find whether the system is in a Coulomb blockade state greatly affects the thermal rectification coefficient. As the average temperature increases or the intradot Coulomb interaction decreases, the system gradually escapes from the Coulomb blockade state, resulting in a reversal of the thermal rectification direction and ultimately leading to an increase in the rectification coefficient. Thirdly, we also find that the Zeeman splitting can be utilized to modulate the behavior of thermal rectification. Thermal rectification occurs only when Zeeman splitting and spin polarization coexist, and under different spin polarizations, the rectification coefficient exhibits different trends with the change of Zeeman splitting. These observations indicate that this structure holds potential application at a thermal rectifier as well as a thermal detector of magnetic fields.","PeriodicalId":508829,"journal":{"name":"New Journal of Physics","volume":"67 24","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141663042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0