Science China Physics, Mechanics & Astronomy最新文献_第2页

Ultrafast phonon hardening and nonthermal lattice potential reconstruction in the charge-density-wave material 1T-TiSe2 电荷密度波材料1T-TiSe2的超快声子硬化和非热晶格势重建

IF 7.5 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2026-04-28 DOI: 10.1007/s11433-026-2952-3

Xue-Qing Ye, Hao Liu, Qi-Yi Wu, Chen Zhang, Xiao-Fang Tang, Bo Chen, Chuan-Cun Shu, Hai-Yun Liu, Yu-Xia Duan, Peter M. Oppeneer, Jian-Qiao Meng

{"title":"Ultrafast phonon hardening and nonthermal lattice potential reconstruction in the charge-density-wave material 1T-TiSe2","authors":"Xue-Qing Ye, Hao Liu, Qi-Yi Wu, Chen Zhang, Xiao-Fang Tang, Bo Chen, Chuan-Cun Shu, Hai-Yun Liu, Yu-Xia Duan, Peter M. Oppeneer, Jian-Qiao Meng","doi":"10.1007/s11433-026-2952-3","DOIUrl":"10.1007/s11433-026-2952-3","url":null,"abstract":"<div>We investigate the nonequilibrium electronic and lattice dynamics of the charge-density-wave (CDW) compound 1T-TiSe2 using ultrafast optical spectroscopy over a wide range of temperatures and pump fluences. We reveal a close relationship between the observed ultrafast dynamical processes and two characteristic temperatures: TCDW (∼202 K) and T* (∼165 K). Two coherent phonon modes are identified: a high-frequency A1g mode (ω1) and a lower-frequency A1g-CDW amplitude mode (ω2). While both modes soften with increasing temperature, in contrast to thermal behavior we observe a pronounced fluence-induced hardening of the CDW amplitude mode on sub-picosecond timescales. This anomalous frequency upshift provides direct evidence for a nonthermal reconstruction of the lattice potential, driven by transient screening of electron-phonon renormalization by the photoexcited carrier plasma. Concomitantly, the excited-state buildup time exhibits an abrupt increase above a well-defined critical fluence below the CDW transition temperature, signaling a qualitative change in carrier relaxation dynamics. The coincidence between phonon hardening and the fluence threshold indicates that ultrafast electronic screening reshapes the effective lattice potential underlying the CDW order, promoting a nonequilibrium metallic-like response without thermal melting. Our results establish ultrafast phonon hardening as a sensitive probe of lattice potential reconstruction and highlight the fragile balance between excitonic correlations and lattice dynamics in photoexcited 1T-TiSe2.</div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"69 6","pages":""},"PeriodicalIF":7.5,"publicationDate":"2026-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829908","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

Non-Hermitian topology in a single driven-dissipative Kerr-cat qubit 单驱动耗散Kerr-cat量子比特中的非厄米拓扑

IF 7.5 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2026-04-28 DOI: 10.1007/s11433-025-2933-x

Pei-Rong Han, Huiye Qiu, Hao-Long Zhang, Wen Ning, Zhen-Biao Yang, Shi-Biao Zheng

{"title":"Non-Hermitian topology in a single driven-dissipative Kerr-cat qubit","authors":"Pei-Rong Han, Huiye Qiu, Hao-Long Zhang, Wen Ning, Zhen-Biao Yang, Shi-Biao Zheng","doi":"10.1007/s11433-025-2933-x","DOIUrl":"10.1007/s11433-025-2933-x","url":null,"abstract":"<div>The intriguing physical phenomena associated with exceptional points have established non-Hermitian physics as a frontier of modern research. Recent investigations have extended non-Hermitian physics into the fully quantum domain. However, existing studies predominantly concentrate on discrete-variable quantum systems, while non-Hermitian quantum effects in continuous-variable encoded systems remain largely unexplored. In this work, we investigate the exceptional structure for a driven-dissipative Kerr-cat qubit, realized with a Kerr nonlinear resonator. We find that the dissipation leads to a bidirectional jump between the two basis states of the cat qubit, which is in distinct contrast with the unidirectional jump associated with normal two-level systems. The competition between this jump and a single-photon drive gives rise to the emergence of third-order Liouvillian exceptional points (LEP3s), each of which corresponds to a crossing point of two lines of LEP2s. Crucially, the single-photon drive is essential for generating the observed nontrivial Liouvillian topology, which reduces to a trivial case when the drive is turned off. We further show that the LEP3 can exhibit the topological character of the Hamiltonian EP3s, which cannot be realized with a single qubit. Our work opens the possibility of realizing non-Hermitian phenomena with continuous-variable quantum systems.</div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"69 6","pages":""},"PeriodicalIF":7.5,"publicationDate":"2026-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829991","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

A hypersphere-like non-Abelian Yang monopole and its topological characterization 一类超球样非阿贝尔杨单极子及其拓扑表征

IF 7.5 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2026-04-28 DOI: 10.1007/s11433-025-2936-1

Shou-Bang Yang, Pei-Rong Han, Wen Ning, Fan Wu, Zhen-Biao Yang, Shi-Biao Zheng

引用次数: 0

Optomagnetically induced transparency and absorption in an actively driven cavity optomagnonic system 主动驱动腔光磁系统的光磁诱导透明和吸收

IF 7.5 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2026-04-28 DOI: 10.1007/s11433-025-2924-4

Wei-Jiang Wu, Qi Hong, Zi-Qi Wang, Yuan-Peng Peng, Yi-Pu Wang, Jian-Qiang You

引用次数: 0

Experimental robustness benchmarking of quantum neural networks on a superconducting quantum processor 量子神经网络在超导量子处理器上的鲁棒性测试

IF 7.5 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2026-04-27 DOI: 10.1007/s11433-025-2943-6

Hai-Feng Zhang, Zhao-Yun Chen, Peng Wang, Liang-Liang Guo, Tian-Le Wang, Xiao-Yan Yang, Ren-Ze Zhao, Ze-An Zhao, Sheng Zhang, Lei Du, Hao-Ran Tao, Zhi-Long Jia, Wei-Cheng Kong, Huan-Yu Liu, Athanasios V. Vasilakos, Yang Yang, Yu-Chun Wu, Ji Guan, Peng Duan, Guo-Ping Guo

{"title":"Experimental robustness benchmarking of quantum neural networks on a superconducting quantum processor","authors":"Hai-Feng Zhang, Zhao-Yun Chen, Peng Wang, Liang-Liang Guo, Tian-Le Wang, Xiao-Yan Yang, Ren-Ze Zhao, Ze-An Zhao, Sheng Zhang, Lei Du, Hao-Ran Tao, Zhi-Long Jia, Wei-Cheng Kong, Huan-Yu Liu, Athanasios V. Vasilakos, Yang Yang, Yu-Chun Wu, Ji Guan, Peng Duan, Guo-Ping Guo","doi":"10.1007/s11433-025-2943-6","DOIUrl":"10.1007/s11433-025-2943-6","url":null,"abstract":"<div>Quantum machine learning (QML) models, like their classical counterparts, are intrinsically vulnerable to adversarial attacks, hindering their secure deployment. Here, we report the first systematic experimental benchmark of robustness for 20-qubit quantum neural network (QNN) classifiers executed on a superconducting processor. Our benchmarking protocol features an efficient adversarial attack algorithm tailored for quantum hardware, enabling the diagnosis of QNN’s robustness across diverse datasets. The empirical upper bound extracted from our attack experiments deviates by only 3 × 10−3 from the analytical lower bound, providing strong experimental confirmation of our attack’s precision and the tightness of the fidelity-based robustness bounds. Furthermore, our quantitative analysis reveals that adversarial training mitigates sensitivity to targeted perturbations by regularizing input gradients, thereby significantly enhancing QNN robustness. Additionally, we observe that experimentally measured QNNs exhibit higher adversarial robustness than classical neural networks, an effect attributed to inherent quantum noise. Our work establishes the first scalable and experimentally accessible framework for robustness benchmarking, paving the way for secure and reliable QML applications.</div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"69 6","pages":""},"PeriodicalIF":7.5,"publicationDate":"2026-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829984","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

Enhancing early detection and localization of gravitational waves via eccentricity-induced higher harmonic modes with 2G detector networks 利用2G探测器网络通过偏心诱发的高谐波模式增强引力波的早期探测和定位

IF 7.5 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2026-04-27 DOI: 10.1007/s11433-025-2931-4

Tao Yang, Rong-Gen Cai, Zhoujian Cao, Hyung Mok Lee

{"title":"Enhancing early detection and localization of gravitational waves via eccentricity-induced higher harmonic modes with 2G detector networks","authors":"Tao Yang, Rong-Gen Cai, Zhoujian Cao, Hyung Mok Lee","doi":"10.1007/s11433-025-2931-4","DOIUrl":"10.1007/s11433-025-2931-4","url":null,"abstract":"<div>Early detection and localization of gravitational waves (GWs) are essential for identifying electromagnetic (EM) counterparts, playing a key role in multi-messenger astronomy. However, second-generation (2G) ground-based detectors are most sensitive to frequencies of tens to hundreds of hertz, limiting the in-band duration of GW signals to O(0.1) to several tens of seconds. This constraint hinders early-warning capabilities and early localization. We present the first theoretical study on how eccentricity-induced higher harmonic modes, which enter the detector band significantly earlier than the dominant mode, enhance early detection and localization in a 2G detector network. By decomposing each harmonic mode in the frequency domain and tracking their sequential entry into the detector band, we analyze the evolution of the average signal-to-noise ratios (SNRs) and localization accuracy as functions of time-to-merger. For a GW170817-like BNS, an eccentricity of e0 = 0.4 at 10 Hz allows the signal to reach SNR 4 and the detection threshold of SNR 8 approximately 12 and 5 min before merger, respectively—gains of 4.5 and 1.5 min over the circular case. Localization within 1000(100)deg2 is achievable 5 (1) min before merger, improving by 2 min (15 s). Our results highlight the potential of eccentricity-induced higher harmonics in improving early warnings and localization, particularly for BNS mergers, enhancing the prospects for multi-messenger astronomy.</div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"69 6","pages":""},"PeriodicalIF":7.5,"publicationDate":"2026-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147829983","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

Tracing the disentangled charge and spin fluctuations in ferromagnetic CrGeTe3 with charge gap evolution 用电荷隙演化追踪铁磁性CrGeTe3的解纠缠电荷和自旋涨落

IF 7.5 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2026-04-24 DOI: 10.1007/s11433-026-2939-x

Fan Wu, Xuefeng Zhang, Zhian Xu, Yanfeng Guo, Zhongkai Liu, Gang Li

{"title":"Tracing the disentangled charge and spin fluctuations in ferromagnetic CrGeTe3 with charge gap evolution","authors":"Fan Wu, Xuefeng Zhang, Zhian Xu, Yanfeng Guo, Zhongkai Liu, Gang Li","doi":"10.1007/s11433-026-2939-x","DOIUrl":"10.1007/s11433-026-2939-x","url":null,"abstract":"<div>The interplay between electronic correlation and magnetism in transition-metal compounds is a topic of great importance in condensed matter physics. These two driving forces are often highly entangled, making it difficult to separate their effects macroscopically in real materials. Visualizing the individual influence of these mechanisms in magnetic materials has proven challenging. In this study, we propose a protocol to characterize the leading couplings in correlated magnetic materials. By combining surface electron-dosing in angle-resolved photoemission spectroscopy with advanced many-body calculations, we investigate the cooperation and competition between electronic correlation and magnetism in van der Waals (vdW) ferromagnetic CrGeTe3. Our results on the charge-gap evolution strongly reveal the persistence of local moment fluctuations on an interacting background of electrons as the leading couplings that fundamentally determine the electronic structure. Our findings provide a realistic route to qualitatively disassemble the interplay between charge and spin fluctuations in low-dimensional ferromagnetic materials, with potential implications for spintronic applications that utilize them individually. This work represents a significant step forward in our understanding of the complex relationship between electronic correlation and magnetism in transition-metal compounds.</div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"69 6","pages":""},"PeriodicalIF":7.5,"publicationDate":"2026-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796359","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

Multiple quantum entanglement empowering quantum technology 多重量子纠缠赋能量子技术

IF 7.5 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2026-04-23 DOI: 10.1007/s11433-026-2932-x

Yuhang Zhao

引用次数: 0

Thermoelectricity and spin caloritronics in the Pt/α-RuCl3 heterostructure Pt/α-RuCl3异质结构中的热电性和自旋热电子

IF 7.5 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2026-04-22 DOI: 10.1007/s11433-025-2935-8

Linhao Jia, Di Chen, Bingcheng Luo, Shaomian Qi, Yuxin Zhai, Shiqiang Liu, Zhongchen Xu, Quanliang Zhu, Guijuan Liu, Shaobo Liu, Yingqi Wang, Yuanjun Song, Jiankun Li, Ryuichi Namba, Kumpei Imamura, Kenichiro Hashimoto, Takasada Shibauchi, Qihua Xiong, Youguo Shi, Y. Matsuda, X. C. Xie, Jian-Hao Chen

{"title":"Thermoelectricity and spin caloritronics in the Pt/α-RuCl3 heterostructure","authors":"Linhao Jia, Di Chen, Bingcheng Luo, Shaomian Qi, Yuxin Zhai, Shiqiang Liu, Zhongchen Xu, Quanliang Zhu, Guijuan Liu, Shaobo Liu, Yingqi Wang, Yuanjun Song, Jiankun Li, Ryuichi Namba, Kumpei Imamura, Kenichiro Hashimoto, Takasada Shibauchi, Qihua Xiong, Youguo Shi, Y. Matsuda, X. C. Xie, Jian-Hao Chen","doi":"10.1007/s11433-025-2935-8","DOIUrl":"10.1007/s11433-025-2935-8","url":null,"abstract":"<div>Since the prediction of a Kitaev interaction–induced quantum spin liquid state, α-RuCl3—a honeycomb lattice material with an effective spin of Seff=1/2—has emerged as a leading candidate for realizing the Kitaev quantum spin liquid. Although extensive thermal and magnetic studies have been carried out on bulk α-RuCl3, experimental investigations on thin films remain scarce. Here, we fabricated nonlocal Pt/α-RuCl3 heterostructures to probe thermal and spin current transport in α-RuCl3 thin flakes. A thermal current deflection in α-RuCl3 is observed using the Nernst effect signal of Pt electrodes. Furthermore, the antiferromagnetic phase boundary is identified from thermal spin current signals. Our results establish an effective approach to accessing thermal and spin properties in layered quantum spin liquid candidates.</div>","PeriodicalId":774,"journal":{"name":"Science China Physics, Mechanics & Astronomy","volume":"69 6","pages":""},"PeriodicalIF":7.5,"publicationDate":"2026-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147796397","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

Scalar perturbation around a rotating Kalb-Ramond BTZ black hole 旋转卡布-雷蒙BTZ黑洞周围的标量扰动

IF 7.5 1区物理与天体物理

Science China Physics, Mechanics & Astronomy Pub Date : 2026-04-22 DOI: 10.1007/s11433-025-2921-y

Zhong-Wu Xia, Sheng Long, Huajie Gong, Qiyuan Pan, Jiliang Jing

引用次数: 0