Mesoscale and Nanoscale Physics
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Showing new listings for Thursday, 25 September 2025
- [1] arXiv:2509.19433 [cn-pdf, pdf, html, other]
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Title: Unifying framework for non-Hermitian and Hermitian topology in driven-dissipative systemsTitle: 驱动耗散系统中非厄米和厄米拓扑的统一框架Comments: main text: 9 pages, 4 figures. Comments welcome!Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ; Optics (physics.optics) ; Quantum Physics (quant-ph)
Recently, a one-to-one correspondence between non-trivial non-Hermitian topology and directional amplification has been demonstrated, theoretically and experimentally, for the case of one complex band. Here, we extend our framework to multiple bands and higher spatial dimension. This proves to be far from trivial. Building on the singular value decomposition, we introduce a new quantity that we dub generalised singular spectrum (GSS). The GSS allows us to define physically meaningful bands related to the system's scattering behaviour and to define invariants for novel notions of point gaps (non-Hermitian topology) and line gaps (Hermitian-like topology), respectively. For both invariants, we prove a bulk-boundary correspondence and show that they give rise to two different kinds of topological edge modes. We illustrate our results with a 1D non-Hermitian Su-Schrieffer-Heeger (SSH) model and a 2D non-Hermitian model that features corner-to-corner amplification. Our work is relevant for many state-of-the-art experimental platforms and it sets the stage for applications such as novel directional amplifiers and non-reciprocal sensors.
最近，人们在理论上和实验上展示了非平凡非厄米拓扑与方向性放大的一一对应关系，针对一个复数带的情况。 在这里，我们将框架扩展到多个带和更高空间维度。 这远非显而易见。 基于奇异值分解，我们引入了一个新量，我们称之为广义奇异谱（GSS）。 GSS使我们能够定义与系统散射行为相关的物理上有意义的能带，并分别定义用于新型点隙（非厄米拓扑）和线隙（类似厄米拓扑）概念的不变量。 对于这两种不变量，我们证明了体-边界对应关系，并表明它们会产生两种不同种类的拓扑边缘模式。 我们通过一个一维非厄米Su-Schrieffer-Heeger（SSH）模型和一个具有端到端放大的二维非厄米模型来说明我们的结果。 我们的工作对于许多最先进的实验平台具有相关性，并为应用奠定了基础，例如新型方向性放大器和非互易传感器。
- [2] arXiv:2509.19437 [cn-pdf, pdf, html, other]
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Title: Quantum Dynamics of Electron Scattering from SkyrmionsTitle: 电子散射的量子动力学Comments: 14 pages, 8 figures, 1 tableSubjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ; Materials Science (cond-mat.mtrl-sci) ; Quantum Physics (quant-ph)
Scattering of electrons from chiral spin textures such as the skyrmions is an emerging research area due to its richness in topological quantum transport, which is significant for spintronic devices. We study the dynamical process of scattering of the spin-$\frac{1}{2}$ particles in the form of Gaussian wavepackets from skyrmions with the aid of the non-relativistic time-dependent Schr\"odinger equation. The scattering cross section shows a rich angular dependence and is deterministically influenced by the iterative flipping of the spin state inside the skyrmion. The latter leads to a set of non-trivial outcomes which include finite transmission and reflection probabilities irrespective of interaction strength, formation of secondary wavefronts associated with back-converted spin components, and a long-lived quasi-bound state at the scattering center. In addition to the rich and intriguing physics, the numerical recipe developed here can be easily adopted for any arbitrary spin texture, which will prepare a playground to explore tunable spin transport.
电子从手性自旋结构如磁涡旋的散射是一个新兴的研究领域，由于其在拓扑量子输运方面的丰富性，这对自旋电子器件具有重要意义。 我们借助非相对论时间依赖的薛定谔方程，研究了自旋-$\frac{1}{2}$粒子以高斯波包形式从磁涡旋散射的动力学过程。 散射截面表现出丰富的角度依赖性，并受到磁涡旋内部自旋状态的迭代翻转的确定性影响。 后者导致了一系列非平凡的结果，包括无论相互作用强度如何都存在有限的透射和反射概率，与反向转换的自旋分量相关的次级波前的形成，以及散射中心处的长寿命准束缚态。 除了丰富的有趣物理现象，这里开发的数值方法可以轻松应用于任何任意自旋结构，这将为探索可调自旋输运提供一个实验平台。
- [3] arXiv:2509.19483 [cn-pdf, pdf, html, other]
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Title: Electrical detection of magnons with nanoscale magnetic tunnel junctionsTitle: 纳米尺度磁隧道结中自旋波的电检测Christopher Heins, Zeling Xiong, Attila Kákay, Joo-Von Kim, Thibaut Devolder, Aleksandra Titova, Johannes Müller, René Hübner, Andreas Worbs, Ryszard Narkowicz, Jürgen Fassbender, Katrin Schultheiss, Helmut SchultheissSubjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Present information and communication technologies are largely based on electronic devices, which suffer from heat generation and high power consumption. Alternatives like spintronics and magnonics, which harness the spin degree of freedom, offer compelling pathways to overcome these fundamental limitations of charge-based electronics. Magnonics relies on spin waves, the collective excitations of magnetic moments in magnetically ordered materials, to achieve processing and transport of information at microwave frequencies without relying on charge currents. However, efficient means for all-electrical, high-resolution, semiconductor-compatible readout of information encoded in spin waves are still missing. Here, we demonstrate the electrical detection of spin waves using a nanoscale magnetic tunnel junction (MTJ) cell fabricated in a state-of-the-art complementary metal-oxide-semiconductor (CMOS) production line. By engineering the dynamic coupling between spin waves and the magnetization state of the MTJ, we demonstrate transduction of spin-wave excitations into measurable electrical signals with high fidelity. Moreover, through these measurements, we find spectral line widths, associated with nonlinear processes, down to a few hundreds of kHz, which opens up new perspectives for spin waves as quantum transducers.
目前的信息和通信技术主要基于电子器件，这些器件存在发热和高功耗的问题。 自旋电子学和磁子学等替代方案，利用自旋自由度，为克服基于电荷的电子器件的基本限制提供了有吸引力的途径。 磁子学依赖于自旋波，即磁序材料中磁矩的集体激发，在微波频率下实现信息的处理和传输，而无需依赖电荷电流。 然而，目前仍缺乏高效、高分辨率、与半导体兼容的全电气读出方法，用于读取编码在自旋波中的信息。 在此，我们展示了使用在最先进的互补金属氧化半导体（CMOS）生产线上制造的纳米尺度磁隧道结（MTJ）单元对自旋波进行电气检测。 通过设计自旋波与MTJ磁化状态之间的动态耦合，我们实现了将自旋波激发转换为可测量的电信号，并具有高保真度。 此外，通过这些测量，我们发现与非线性过程相关的谱线宽度低至几百千赫兹，这为自旋波作为量子转导器开辟了新的前景。
- [4] arXiv:2509.19537 [cn-pdf, pdf, html, other]
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Title: Rapid Autotuning of a SiGe Quantum Dot into the Single-Electron Regime with Machine Learning and RF-Reflectometry FPGA-Based MeasurementsTitle: 基于机器学习和射频反射测量的FPGA方法快速自调制硅锗量子点进入单电子区域Marc-Antoine Roux, Joffrey Rivard, Victor Yon, Alexis Morel, Dominic Leclerc, Claude Rohrbacher, El Bachir Ndiaye, Felice Francesco Tafuri, Brendan Bono, Stefan Kubicek, Roger Loo, Yosuke Shimura, Julien Jussot, Clément Godfrin, Danny Wan, Kristiaan De Greve, Marc-André Tétrault, Dominique Drouin, Christian Lupien, Michel Pioro-Ladrière, Eva Dupont-FerrierComments: 9 pages, 5 figuresSubjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ; Quantum Physics (quant-ph)
Spin qubits need to operate within a very precise voltage space around charge state transitions to achieve high-fidelity gates. However, the stability diagrams that allow the identification of the desired charge states are long to acquire. Moreover, the voltage space to search for the desired charge state increases quickly with the number of qubits. Therefore, faster stability diagram acquisitions are needed to scale up a spin qubit quantum processor. Currently, most methods focus on more efficient data sampling. Our approach shows a significant speedup by combining measurement speedup and a reduction in the number of measurements needed to tune a quantum dot device. Using an autotuning algorithm based on a neural network and faster measurements by harnessing the FPGA embedded in Keysight's Quantum Engineering Toolkit (QET), the measurement time of stability diagrams has been reduced by a factor of 9.8. This led to an acceleration factor of 2.2 for the total initialization time of a SiGe quantum dot into the single-electron regime, which is limited by the Python code execution.
自旋量子位需要在电荷态转变周围的非常精确的电压空间内运行，以实现高保真度的门操作。 然而，允许识别所需电荷态的稳定性图获取时间很长。 此外，随着量子位数量的增加，用于搜索所需电荷态的电压空间迅速扩大。 因此，需要更快的稳定性图获取来扩展自旋量子位量子处理器。 目前，大多数方法集中在更高效的数据采样上。 我们的方法通过结合测量加速和减少调整量子点设备所需的测量次数，实现了显著的加速。 使用基于神经网络的自动调谐算法，并利用Keysight的量子工程工具包(QET)中的FPGA进行更快的测量，稳定性图的测量时间已减少9.8倍。 这使得硅锗量子点进入单电子区域的总初始化时间加速了2.2倍，这受限于Python代码的执行。
- [5] arXiv:2509.19706 [cn-pdf, pdf, html, other]
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Title: Harmonic and Subharmonic Magnon Generation in a Surface Acoustic Wave ResonatorTitle: 表面声波谐振器中的磁振子谐波和次谐波生成Yunyoung Hwang, Liyang Liao, Jorge Puebla, Marco Brühlmann, Carlos Gonzalez-Ballestero, Kouta Kondou, Naoki Ogawa, Sadamichi Maekawa, Yoshichika OtaniComments: 5 pages, 4 figuresSubjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ; Other Condensed Matter (cond-mat.other)
We experimentally observe the generation of magnon harmonics and subharmonics in an on-chip surface acoustic wave resonator incorporating a thin Co$_{20}$Fe$_{60}$B$_{20}$ film, using micro-focused Brillouin light scattering. In our devices, rotating the in-plane magnetic field allows continuous tuning of the magnon-phonon coupling from weak to strong within the same resonator. In the weak coupling regime, we only observe fundamental magnetoelastic wave signal at $f_{1}$. Conversely, in the strong coupling regime, in addition to the fundamental magnetoelastic wave, we observe subharmonic and harmonic signals at $3/2f_{1}$, $2f_{1}$, and $3f_{1}$, which are well reproduced by our analytical model. Our results establish phonons as a means to generate and control nonlinear magnons in the strong coupling regime, providing a new route for magnonic signal processing.
我们通过使用微聚焦布里渊光散射，在集成有薄层Co$_{20}$Fe$_{60}$B$_{20}$薄膜的片上表面声波谐振器中，实验观察到了磁振子谐波和次谐波的产生。 在我们的器件中，旋转面内磁场可以在同一谐振器中连续调节磁振子-声子耦合从弱到强。 在弱耦合区域，我们仅在$f_{1}$处观察到基本的磁弹性波信号。 相反，在强耦合区域，除了基本的磁弹性波外，我们还在$3/2f_{1}$、$2f_{1}$和$3f_{1}$处观察到次谐波和谐波信号，这些信号由我们的解析模型很好地再现。 我们的结果确立了声子作为在强耦合区域生成和控制非线性磁振子的一种手段，为磁子信号处理提供了一条新途径。
- [6] arXiv:2509.19735 [cn-pdf, pdf, html, other]
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Title: Projective crystal symmetry and topological phasesTitle: 投影晶体对称性和拓扑相Comments: 8 pages, 3 figures, to be published in Materials Today QuantumSubjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Quantum states naturally represent symmetry groups, though often in a projective sense. Intriguingly, the projective nature of crystalline symmetries has remained underexplored until very recently. A series of groundbreaking theoretical and experimental studies have now brought this to light, demonstrating that projective representations of crystal symmetries lead to remarkable consequences in condensed matter physics and various artificial crystals, particularly in their connection to topological phenomena. In this article, we explain the basic ideas and notions underpinning these recent developments and share our perspective on this emerging research area. We specifically highlight that the appearance of momentum-space nonsymmorphic symmetry is a unique feature of projective crystal symmetry representations. This, in turn, has the profound consequence of reducing the fundamental domain of momentum space to all possible flat compact manifolds, which include torus and Klein bottle in 2D and the ten platycosms in 3D, presenting a significantly richer landscape for topological structures than conventional settings. Finally, the ongoing efforts and promising future research directions are discussed.
量子态自然地表示对称群，尽管通常是以投影的方式。 引人注目的是，晶体对称性的投影性质直到最近才被深入研究。 一系列开创性的理论和实验研究现在已经揭示了这一点，表明晶体对称性的投影表示在凝聚态物理和各种人工晶体中导致了显著的结果，特别是在它们与拓扑现象的联系方面。 在本文中，我们解释了这些最新进展所依据的基本思想和概念，并分享了我们对这一新兴研究领域的观点。 我们特别强调，动量空间中的非对称对称性的出现是投影晶体对称性表示的独特特征。 反过来，这使得动量空间的基本域减少到所有可能的平坦紧致流形，包括二维中的环面和克莱因瓶，以及三维中的十种平宇宙，为拓扑结构提供了比传统设置更为丰富的景观。 最后，讨论了正在进行的努力和有前景的研究方向。
- [7] arXiv:2509.19741 [cn-pdf, pdf, html, other]
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Title: Domain wall skyrmion-based magnonic crystalTitle: 基于畴壁斯格明子的磁振子晶体Comments: 8 pages, 5figuresSubjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Magnonic waveguide based on domain wall (DW) is considered as a crucial breakthrough toward the realization of magnonic nanocircuits. However, the effective control of spin waves propagating in DWs remains to be explored. Here, we construct a magnonic crystal (MC) by using a chain of the domain wall skyrmions (DWSKs) to manipulate the spin-wave propagation in DWs. We show that the DWSK chain can be created by leveraging voltage-controlled Dzyaloshinskii-Moriya interaction. The DWSK-based MC opens magnonic bandgaps, which can be dynamically adjusted through magnetic fields modulating the DWSK size. Furthermore, the manipulation of spin waves by the DWSK-based MC maintains robust in curved DW, demonstrating its adaptability to complex device architectures. Our work provides an effective method to control the spin-wave propagation in DWs and paves the way for designing energy-efficient magnonic nanocircuits.
基于畴壁（DW）的磁振子波导被认为是实现磁振子纳米电路的关键突破。 然而，对在DW中传播的自旋波的有效控制仍有待探索。 在此，我们通过使用畴壁斯格明子（DWSK）链来构建磁振子晶体（MC），以操控DW中的自旋波传播。 我们表明，可以通过电压控制的Dzyaloshinskii-Moriya相互作用来创建DWSK链。 基于DWSK的MC会打开磁振子带隙，这些带隙可以通过调节DWSK大小的磁场进行动态调整。 此外，基于DWSK的MC对弯曲DW中的自旋波的操控具有鲁棒性，证明了其在复杂器件架构中的适应性。 我们的工作提供了一种有效控制DW中自旋波传播的方法，并为设计节能的磁振子纳米电路铺平了道路。
- [8] arXiv:2509.19825 [cn-pdf, pdf, html, other]
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Title: $\mathbb{Z}_2$ topological invariant in three-dimensional PT- and PC-symmetric class CI band structuresTitle: $\mathbb{Z}_2$三维PT和PC对称类CI能带结构中的拓扑不变量Comments: 17 pagesSubjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
We construct a previously missing $\mathbb{Z}_2$ topological invariant for three-dimensional band structures in symmetry class CI defined by parity-time (PT) and parity-particle-hole (PC) symmetries. PT symmetry allows one to define a real Berry connection and, based on the $\eta$-invariant, a spin-Chern--Simons (spin-CS) action. We show that PC symmetry quantizes the spin-CS action to $\{0,2\pi\}$ with $4\pi$ periodicity, thereby yielding a well-defined $\mathbb{Z}_2$ invariant. This invariant is additive under direct sums of isolated band structures, reduces to a known $\mathbb{Z}_2$ index when a global Takagi factorization exists, and in general depends on the choice of spin structure. Finally, we demonstrate lattice models in which this newly introduced $\mathbb{Z}_2$ invariant distinguishes topological phases that cannot be detected by the previously known topological indices.
我们为由宇称-时间(PT)和宇称-粒子空穴(PC)对称性定义的三维能带结构的对称性类CI构造了一个之前缺失的$\mathbb{Z}_2$拓扑不变量。PT对称性允许定义一个实数贝里连接，并基于$\eta$不变量，定义一个自旋-Chern--Simons（自旋-CS）作用量。我们证明PC对称性将自旋-CS作用量量化为$\{0,2\pi\}$，具有$4\pi$周期性，从而得到一个定义良好的$\mathbb{Z}_2$不变量。该不变量在孤立能带结构的直和下是可加的，当存在全局Takagi分解时，会退化为已知的$\mathbb{Z}_2$指标，并且通常依赖于自旋结构的选择。最后，我们展示了这种新引入的$\mathbb{Z}_2$不变量可以区分之前已知拓扑指标无法检测到的拓扑相。
- [9] arXiv:2509.19932 [cn-pdf, pdf, html, other]
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Title: Exploration of Altermagnetism in $\mathrm{RuO_{2}}$Title: $\mathrm{RuO_{2}}$中的反铁磁性的探索Comments: 23 pages, 9 figures, 1 tableSubjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ; Materials Science (cond-mat.mtrl-sci)
The fundamental role of magnetic materials in modern science and technology has driven a rapid surge in research on unconventional magnetism in recent years. In particular, altermagnets, which simultaneously exhibit zero net magnetization in real space and anisotropic spin splitting in momentum space, have garnered significant interest for both fundamental physics and technological applications. Among these, $\mathrm{RuO_{2}}$ stands as the pioneering and most extensively studied altermagnet. While the intrinsic magnetic order of $\mathrm{RuO_{2}}$ is still a subject of active debate, numerous exotic phenomena characteristic of altermagnetism have been observed in $\mathrm{RuO_{2}}$ samples. In this review, we explore each facet of the altermagnetism through specific case studies in $\mathrm{RuO_{2}}$, systematically surveying its crystal and magnetic structures, electronic band properties, and transport phenomena. We critically assess the debate surrounding the intrinsic magnetism in $\mathrm{RuO_{2}}$, incorporating evidence from altermagnetic signatures in transport, as well as contrasting results from magnetic and spectroscopic measurements. Finally, possible future research directions in this field are discussed.
磁性材料在现代科学和技术中的基础作用近年来推动了对非常规磁性研究的迅速增长。 特别是，反铁磁体，在实空间中表现出零净磁化，在动量空间中表现出各向异性自旋分裂，由于其在基础物理和技术应用中的重要性而引起了广泛关注。 其中，$\mathrm{RuO_{2}}$作为开创性和研究最广泛的反铁磁体而存在。 尽管$\mathrm{RuO_{2}}$的本征磁序仍处于积极讨论中，但在$\mathrm{RuO_{2}}$样品中已经观察到了反铁磁性特有的多种奇异现象。 在本综述中，我们通过$\mathrm{RuO_{2}}$中的具体案例研究，探讨反铁磁性的各个方面，系统地调查其晶体和磁结构、电子能带特性以及输运现象。 我们对$\mathrm{RuO_{2}}$中本征磁性的争论进行了批判性评估，结合了输运中的反铁磁特征证据，以及磁性和光谱测量的对比结果。 最后，讨论了该领域可能的未来研究方向。
- [10] arXiv:2509.19978 [cn-pdf, pdf, html, other]
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Title: Non-ohmic to ohmic crossover in the breakdown of the quantum Hall states in graphene under broadband excitationsTitle: 宽带激发下石墨烯量子霍尔态击穿中的非欧姆到欧姆转变Torsten Röper, Aifei Zhang, Kenji Watanabe, Takashi Taniguchi, Olivier Maillet, François D. Parmentier, Erwann BocquillonComments: Main text (6 pages, 4 figures) and Supplementary materialSubjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Graphene, through the coexistence of large cyclotron gaps and small spin and valley gaps, offers the possibility to study the breakdown of the quantum Hall effect across a wide range of energy scales. In this work, we investigate the breakdown of the QHE in high-mobility graphene Corbino devices under broadband excitation ranging from DC up to 10 GHz. We find that the conductance is consistently described by variable range hopping (VRH) and extract the hopping energies from both temperature and field-driven measurements. Using VRH thermometry, we are able to distinguish between a cold and hot electron regime, which are dominated by non-ohmic VRH and Joule heating, respectively. Our results demonstrate that breakdown in the quantum Hall regime of graphene is governed by a crossover from non-ohmic, field-driven VRH to ohmic, Joule-heating-dominated transport.
石墨烯通过大回旋加速器间隙和小自旋及谷间隙的共存，提供了在广泛的能量尺度上研究量子霍尔效应破坏的可能性。 在本工作中，我们在从直流到10 GHz的宽频激发下，研究了高迁移率石墨烯Corbino器件中的量子霍尔效应的破坏。 我们发现电导率始终可以通过可变范围跳跃（VRH）来描述，并从温度和场驱动的测量中提取跳跃能量。 使用VRH测温法，我们能够区分冷电子和热电子区域，分别由非欧姆VRH和焦耳加热主导。 我们的结果表明，石墨烯量子霍尔区的破坏是由非欧姆、场驱动的VRH向欧姆、焦耳加热主导的输运的交叉所控制的。
- [11] arXiv:2509.19992 [cn-pdf, pdf, html, other]
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Title: Breakdown of symmetry constraint in Floquet topological superconductorTitle: 弗洛凯拓扑超导体中的对称性约束分解Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ; Other Condensed Matter (cond-mat.other)
Topological superconductor is regarded as an ideal candidate for topological quantum computing due to its ability to simulate the enigmatic Majorana fermions that satisfy non-Abelian statistics. Previous studies revealed that symmetry exerts an unbreakable constraint on the existence, classes, and orders of Majorana modes. It severely limits the controllability and application of Majorana modes. Here, we propose a Floquet-engineering method to break this symmetry-imposed constraint on topological phases. By applying periodic driving on a system belonging to a symmetry class that prohibits the existence of first-order topological phases, we find that rich first-order Majorana modes are created. Interestingly, exotic hybrid-order topological superconductors with coexisting first-order Majorana boundary modes and second-order Majorana corner modes not only in two different quasienergy gaps but also in one single gap are generated at ease by the periodic driving. Refreshing the prevailing understanding of symmetry constraint on topological phases, our result opens an avenue for the creation of exotic topological superconductors without altering symmetries. It greatly expands the scope of the fabricated materials that host topological superconductor.
拓扑超导体因其能够模拟满足非阿贝尔统计的神秘马约拉纳费米子，被视为拓扑量子计算的理想候选者。 先前的研究表明，对称性对马约拉纳模式的存在、类别和阶数施加了不可打破的约束。 这严重限制了马约拉纳模式的可控性和应用。 在这里，我们提出一种弗洛凯工程方法，以打破对拓扑相的对称性约束。 通过对属于禁止一阶拓扑相存在的对称类的系统施加周期性驱动，我们发现产生了丰富的第一阶马约拉纳模式。 有趣的是，通过周期性驱动，可以轻松生成具有共存的第一阶马约拉纳边界模式和第二阶马约拉纳角模式的奇异混合阶拓扑超导体，这些模式不仅存在于两个不同的准能量间隙中，也存在于一个单一间隙中。 刷新了对拓扑相上对称性约束的普遍理解，我们的结果为在不改变对称性的前提下创造奇异拓扑超导体开辟了一条新途径。 它极大地扩展了承载拓扑超导体的材料范围。
- [12] arXiv:2509.20061 [cn-pdf, pdf, other]
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Title: Resistive switching behaviors in vertically aligned MoS$_2$ films with Cu, Ag, and Au electrodesTitle: 垂直对齐的MoS$_2$薄膜中铜、银和金电极的电阻切换行为Shuei-De Huang, Touko Lehenkari, Topias Järvinen, Seyed Hossein Hosseini-Shokouh, Farzaneh Bouzari, Krisztian Kordas, Hannu-Pekka KomsaComments: 23 pages, 4 figures, supporting informationSubjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ; Materials Science (cond-mat.mtrl-sci)
Neuromorphic computing circuits can be realized using memristors based on low-dimensional materials enabling enhanced metal diffusion for resistive switching. Here, we investigate memristive properties of vertically aligned MoS$_2$ (VA-MoS$_2$) films with three different metal electrodes: Ag, Cu, and Au. Despite having the same active material, all three metals show distinct switching behavior, which are crucial for neuromorphic computing applications: Ag enables volatile switching, Cu demonstrates stable non-volatile switching with retention over 2500 s, and Au shows no memristive response. Cu devices show abrupt resistance changes, and significant increase of copper content upon biasing, indicative of stable non-volatile switching based on filament formation and rupture. About 85% of Ag and Cu devices exhibit reliable memristor behavior. Our findings provide valuable insights into the memristive switching mechanism in VA-MoS$_2$ and present a promising avenue for facile fabrication of neuromorphic circuits by employing a set of different metals on a single active material.
基于低维材料的忆阻器可以实现神经形态计算电路，该忆阻器增强了金属扩散以用于电阻切换。 在这里，我们研究了垂直对齐的MoS$_2$ (VA-MoS$_2$) 薄膜的忆阻特性，这些薄膜使用三种不同的金属电极：Ag、Cu 和 Au。 尽管具有相同的活性材料，这三种金属均表现出不同的切换行为，这对于神经形态计算应用至关重要： Ag 实现了易失性切换，Cu 展示了在 2500 秒以上的保持时间内稳定的非易失性切换，而 Au 则没有忆阻响应。 Cu 器件表现出突然的电阻变化，并且在偏置下铜含量显著增加，表明基于导电丝形成和断裂的稳定非易失性切换。 约 85% 的 Ag 和 Cu 器件表现出可靠的忆阻器行为。 我们的研究结果为 VA-MoS$_2$中的忆阻切换机制提供了有价值的见解，并通过在一个单一活性材料上采用一组不同的金属，为简便制造神经形态电路提供了一条有前景的途径。
- [13] arXiv:2509.20163 [cn-pdf, pdf, html, other]
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Title: Non-universal localization transition in the quantum Hall effect probed through broken-symmetry states of grapheneTitle: 通过石墨烯的对称性破缺态探测量子霍尔效应中的非普遍局域化转变Aifei Zhang, Torsten Röper, Manjari Garg, Kenji Watanabe, Takashi Taniguchi, Carles Altimiras, Patrice Roche, Erwann Bocquillon, Olivier Maillet, François D. ParmentierSubjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
The quantum Hall effect hosts quantum phase transitions in which the localization length, that is the size of disorder-induced bulk localized states, is governed by universal scaling from percolation theory. However, this universal character is not systematically observed in experiments, including very recent ones in extremely clean devices. Here we explore this non-universality by systematically measuring the localization length in broken-symmetry quantum Hall states of graphene. Depending on the nature and gap size of these states, we observe differences of up to a tenfold in the minimum localization length, accompanied by clear deviations from universal scaling. Our results, as well as the previously observed non-universality, are fully captured by a simple picture based on the co-existence of localized states from two successive sub-Landau levels.
量子霍尔效应包含量子相变，其中局域化长度，即由无序引起的体态局域化的大小，由渗流理论的普遍标度所支配。 然而，这种普遍特性在实验中并未系统观察到，包括在极高纯净度器件中的最新实验。 在这里，我们通过系统测量石墨烯的破缺对称性量子霍尔态中的局域化长度来探索这种非普遍性。 根据这些态的性质和能隙大小，我们观察到最小局域化长度存在高达十倍的差异，并伴随着明显的普遍标度偏离。 我们的结果以及之前观察到的非普遍性，都可以通过一个简单的模型完全描述，该模型基于两个连续子朗道能级产生的局域态共存。
- [14] arXiv:2509.20243 [cn-pdf, pdf, html, other]
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Title: Effects of correlated hopping on thermoelectric response of a quantum dot strongly coupled to ferromagnetic leadsTitle: 相关跳跃对强耦合到铁磁电极的量子点热电响应的影响Journal-ref: Ann. Phys. Vol. 537 (2025)Subjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
We theoretically investigate the impact of correlated hopping on thermoelectric transport through a quantum dot coupled to ferromagnetic leads. Using the accurate numerical renormalization group method, we analyze the transport characteristics, focusing on the interplay between electronic correlations, spin-dependent transport processes, and thermoelectric response. We calculate the electrical conductance and thermopower as functions of the dot energy level, lead polarization, and the amplitude of correlated hopping. Moreover, we analyze the effect of competing correlations on the Kondo resonance and discuss the asymmetry of conductance peaks under the influence of the exchange field. We demonstrate that the presence of correlated hopping is responsible for asymmetric spin-dependent transport characteristics. Our results provide valuable insight into how correlated hopping affects spin-dependent transport and thermoelectric efficiency in quantum dot systems with ferromagnetic contacts.
我们理论研究了关联跃迁对通过耦合到铁磁电极的量子点的热电输运的影响。 使用精确的数值重整化群方法，我们分析了输运特性，重点研究电子关联、自旋依赖的输运过程和热电响应之间的相互作用。 我们计算了电导和热电势作为量子点能级、电极极化和关联跃迁幅度的函数。 此外，我们分析了竞争关联对Kondo共振的影响，并讨论了交换场影响下的电导峰不对称性。 我们证明了关联跃迁的存在导致了自旋依赖的输运特性不对称。 我们的结果为了解关联跃迁如何影响具有铁磁接触的量子点系统中的自旋依赖输运和热电效率提供了有价值的见解。
New submissions (showing 14 of 14 entries )
- [15] arXiv:2509.19320 (cross-list from cond-mat.str-el) [cn-pdf, pdf, html, other]
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Title: Introduction to some of the simplest topological phases of matterTitle: 物质的一些最简单的拓扑相简介Comments: 39 pages, 3 figures, lecture notes from the 2025 Bad Honnef summer school "Symmetry protected topological phases"Subjects: Strongly Correlated Electrons (cond-mat.str-el) ; Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ; Quantum Physics (quant-ph)
These lecture notes explain the classification of some simple fermionic topological phases of matter in a pedestrian manner, with an aim to be maximally pedagogical = doing things in excruciating detail. We focus on a many-body perspective, even if many of the models we work with are non-interacting. We start out with symmetry protected topological (SPT) phases of free fermions that are protected by U(1) symmetry = topological insulators. We then look at fermion topological phases that don't even need a symmetry = topological superconductors, and explain how their classification changes in presence of spinless time-reversal symmetry. We close by perturbatively checking which of the 1D topological phases we had found are stable to interactions.
这些讲义笔记以通俗易懂的方式解释了某些简单费米子拓扑物质相的分类，旨在最大程度地进行教学说明=详细地做每一件事。 我们从多体视角出发，尽管我们使用的许多模型是无相互作用的。 我们首先介绍由U(1)对称性保护的自由费米子的对称性保护拓扑(SPT)相=拓扑绝缘体。 然后我们研究甚至不需要对称性的费米子拓扑相=拓扑超导体，并解释在存在无自旋时间反演对称性的情况下，它们的分类如何变化。 最后，我们通过微扰检查我们找到的1D拓扑相中有哪一些在相互作用下是稳定的。
- [16] arXiv:2509.19764 (cross-list from cond-mat.str-el) [cn-pdf, pdf, html, other]
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Title: A General Many-Body Perturbation Framework for Moiré Systems: Application to Rhombohedral Pentalayer Graphene/hBN HeterostructuresTitle: 一种适用于莫尔系统的通用多体微扰框架：应用于菱形五层石墨烯/六方氮化硼异质结构Comments: 6 pages, 3 figures, 1 table; supp info will be uploaded soonSubjects: Strongly Correlated Electrons (cond-mat.str-el) ; Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Moir\'e superlattices host a rich variety of correlated topological states, including interaction-driven integer and fractional Chern insulators. A common approach to study interacting ground states at integer fillings is the Hartree-Fock mean-field method. However, this method neglects dynamical correlations, which often leads to an overestimation of spontaneous symmetry breaking and fails to provide quantitative descriptions of single-particle excitations. This work introduces a general many-body perturbation framework for moir\'e systems, combining all-band Hartree-Fock calculations with random phase approximation (RPA) correlation energies and $GW$ quasiparticle corrections. We apply this framework to moir\'e superlattice consisted of rhombohedral pentalayer graphene aligned with hexagonal boron nitride. Our all-band Hartree-Fock calculations, which include all plane-wave components up to the high-energy cutoff of the continuum model, reveal a phase diagram at moir\'e filling $\nu=1$ that qualitatively aligns with experimental measurements. Incorporating RPA correlation energy further yields quantitative agreement with the evolution of transport properties across electric fields. The $GW$ quasiparticle bands exhibit significantly reduced gaps and bandwidths compared to Hartree-Fock results, while quasiparticle weights close to unity indicate that the ground state is well-described by a Slater determinant, justifying the qualitative effectiveness of mean-field approaches for integer fillings in this system. Our versatile framework provides a systematic beyond-mean-field approach applicable to generic moir\'e systems.
莫尔超晶格容纳了丰富的相关拓扑态，包括由相互作用驱动的整数和分数陈绝缘体。研究整数填充下的相互作用基态的一种常用方法是哈特里-福克平均场方法。然而，这种方法忽略了动态关联，这通常会导致对自发对称性破缺的高估，并且无法提供单粒子激发的定量描述。这项工作引入了一个适用于莫尔系统的通用多体微扰框架，结合了全带哈特里-福克计算与随机相位近似（RPA）相关能量和$GW$准粒子修正。我们将该框架应用于由菱方五层石墨烯组成的莫尔超晶格，该超晶格与六方氮化硼对齐。我们的全带哈特里-福克计算，包括所有平面波分量直到连续模型的高能截止，揭示了在莫尔填充$\nu=1$下的相图，其定性地与实验测量结果一致。结合RPA相关能量进一步实现了与电场下输运性质演变的定量一致。$GW$准粒子带相比哈特里-福克结果表现出显著减小的带隙和带宽，而接近于单位的准粒子权重表明基态由斯莱特行列式很好地描述，这证明了平均场方法在该系统整数填充下的定性有效性。我们多功能的框架提供了一种适用于一般莫尔系统的系统性超越平均场方法。
- [17] arXiv:2509.19818 (cross-list from cond-mat.mtrl-sci) [cn-pdf, pdf, html, other]
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Title: The orbital-driven topological phase transition and planar Hall responses in ternary tellurides Weyl semi-metalsTitle: 轨道驱动的拓扑相变和三元碲化物外尔半金属中的平面霍尔响应Comments: Main text: 10 pages, 6 figures, SM: 8 pages, 10 figuresSubjects: Materials Science (cond-mat.mtrl-sci) ; Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Here we study electronic properties of the ternary tellurides TaXTe$_4$ (X=Rh, Ir) using density functional theory and investigate chiral anomaly mediated planar Hall response from ab initio calculations. We show that TaRhTe$_4$ is a hybrid Weyl semimetal (WSM), hosting Weyl points (WPs) of both type-I, type-II, while TaIrTe$_4$ is a type-II WSM as it hosts only type-II WPs with spin-orbit couplings (SOC). All WPs lie in the $k_z=0$ plane, and remain well-separated in both momentum and energy landscape. We observe long Fermi arcs connecting Weyl nodes of opposite chirality. We report both SOC and orbital driven topological phase transition in ternary tellurides. TaIrTe$_4$ undergoes topological phase transition under SOC. Whereas orbital driven topological phase transition due to d$_{xz}$ orbital has been observed in TaRhTe$_4$ even without SOC. Furthermore, the evolution of the band structures and the annihilation of WPs due to d$_{xz}$-Ir/Rh orbitals associated with the phase transitions in TaXTe$_4$ are also discussed. This systematic study opens new routes for engineering topological materials relying beyond strong SOC and sheds light on the possible role of correlation effects originating from orbital orbital degree of freedoms in tellurides. We further report an enhancement of planar Hall effects due to orbital driven topological phase transition in TaXTe$_4$ and we make resort to a tight-binding model to correlate the above findings with the effective mass anisotropy in different types of WSMs.
我们使用密度泛函理论研究了三元碲化物TaXTe$_4$（X=Rh, Ir）的电子性质，并通过从头计算研究了手征异常介导的平面霍尔响应。我们表明，TaRhTe$_4$是一种混合外尔半金属（WSM），包含类型-I和类型-II的外尔点（WPs），而TaIrTe$_4$是一种类型-II WSM，因为它仅包含类型-II的WPs，并具有自旋-轨道耦合（SOC）。所有WPs都位于$k_z=0$平面内，并在动量和能量景观中保持良好分离。我们观察到连接相反手性外尔节点的长费米弧。我们报告了三元碲化物中的SOC和轨道驱动拓扑相变。TaIrTe$_4$在SOC下经历拓扑相变。而轨道驱动的拓扑相变由于d$_{xz}$轨道在TaRhTe$_4$中即使没有SOC也被观察到。 此外，还讨论了由于与TaXTe$_4$中相变相关的d$_{xz}$-Ir/Rh轨道导致的能带结构演化和WPs的湮灭。这项系统性研究为工程拓扑材料开辟了新途径，超越了强自旋轨道耦合，并揭示了来自碲化物中轨道自由度的相关效应的可能作用。我们进一步报告了由于TaXTe$_4$中轨道驱动的拓扑相变导致的平面霍尔效应增强，并借助紧束缚模型将上述发现与不同类型的WSMs中的有效质量各向异性联系起来。
- [18] arXiv:2509.20014 (cross-list from physics.app-ph) [cn-pdf, pdf, html, other]
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Title: How to Identify Suitable Gate Dielectrics for Transistors based on Two-Dimensional SemiconductorsTitle: 如何基于二维半导体识别适合的栅极介质Theresia Knobloch, Quentin Smets, Anton E. O. Persson, Pedram Khakbaz, Christoph Wilhelmer, Dennis Lin, Zherui Han, Yunyan Chung, Kevin P. OBrien, Chelsey Dorow, Cormac OCoileain, Mario Lanza, Dominic Waldhoer, Alexander Karl, Kailang Liu, Tianyou Zhai, Hailin Peng, Congwei Tan, Xiao Renshaw Wang, Georg S. Duesberg, John Robertson, Uygar Avci, Iuliana Radu, Eric Pop, Cesar J. Lockhart de la Rosa, Tibor GrasserComments: 21 pages, 4 figures, perspective articleSubjects: Applied Physics (physics.app-ph) ; Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
The recent progress in nanosheet transistors has established two-dimensional (2D) semiconductors as viable candidates for future ultra-scaled electronic devices. Next to reducing contact resistance, identifying good gate dielectrics is a fundamental challenge, as the dielectric/channel interface dramatically impacts virtually all performance parameters. While several promising gate dielectrics have recently been reported, the evaluation of their quality and suitability is often fragmentary and focused on selected important performance metrics of the gate stack, such as the capacitive gate control, leakage currents, reliability, and ease of fabrication and integration. However, identifying a suitable gate stack is a complex problem that has not yet been approached systematically. In this perspective, we aim to formulate general criteria for good gate dielectrics.
近年来，纳米片晶体管的进展已将二维(2D)半导体确立为未来超大规模电子器件的可行候选材料。除了降低接触电阻外，确定良好的栅极介电材料是一个基本挑战，因为介电材料/沟道界面几乎影响所有性能参数。尽管最近已报道了几种有希望的栅极介电材料，但对其质量和适用性的评估通常零散，并且集中在栅极堆叠的一些重要性能指标上，例如电容栅极控制、漏电流、可靠性以及制造和集成的难易程度。然而，确定合适的栅极堆叠是一个复杂的问题，尚未被系统地研究。在本文中，我们旨在制定良好栅极介电材料的一般标准。
- [19] arXiv:2509.20139 (cross-list from cond-mat.mtrl-sci) [cn-pdf, pdf, html, other]
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Title: Intrinsic Electro-Optic Kerr RotationTitle: 内在电光克尔旋转Comments: 6+10 pages, 3+2 figuresSubjects: Materials Science (cond-mat.mtrl-sci) ; Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
We uncover a previously overlooked contribution to the electro-optic Kerr rotation of reflected light, arising from the interplay of matter, the static electric field, and the magnetic component of light. Remarkably, this mechanism dominates in isotropic nonmagnetic homogeneous metals. We derive analytical expressions for the Kerr rotation in both two-dimensional layers and semi-infinite systems. Within the relaxation-time approximation, we predict experimentally accessible signal magnitudes. This intrinsic mechanism thereby opens new opportunities for probing electronic properties in materials through Kerr spectroscopy.
我们揭示了反射光的电光克尔旋转中之前被忽视的贡献，该贡献来源于物质、静态电场和光的磁成分之间的相互作用。 值得注意的是，这种机制在各向同性非磁性均匀金属中占主导地位。 我们推导了二维层和半无限系统中克尔旋转的解析表达式。 在弛豫时间近似下，我们预测了可实验探测的信号大小。 因此，这种内在机制为通过克尔光谱探测材料中的电子性质提供了新的机会。
- [20] arXiv:2509.20156 (cross-list from cond-mat.mtrl-sci) [cn-pdf, pdf, html, other]
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Title: Unveiling the magnetic behavior of C$_{\rm3}$N$_{\rm4}$ 2D material by defect creation, defect passivation, and transition metal adsorptionTitle: 通过缺陷生成、缺陷钝化和过渡金属吸附揭示C$_{\rm3}$N$_{\rm4}$二维材料的磁性行为Subjects: Materials Science (cond-mat.mtrl-sci) ; Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
Using the density functional tight binding method (DFTB) and the GFN1-xTB (Geometries, Frequencies, and Noncovalent interactions Tight Binding) Hamiltonian, we have investigated the structural, electronic and magnetic properties of vacancy defects, hydrogen and oxygen passivated defects, and Fe adsorption in two-dimensional (2D) graphitic carbon nitride (gt-C$_3$N$_4$) 2D material. The ring shape is the most preferred vacancy evolution path, with significant stability of the semicircle fourfold C-N-C-N vacancy. We found that bare gt-C$_3$N$_4$ which is non-magnetic becomes magnetic by 2-, and 5-defects creation, hydrogen/oxygen passivation of the defects, and upon Fe adsorption. Interestingly, Fe atoms interact with the gt-C$_3$N$_4$ sheet and result in a ground ferromagnetic (FM) state. In addition, we investigate the effects of passivating the vacancies by hydrogen in gt-C$_3$N$_4$ on its structural, electrical, and magnetic properties. We found that substituting the 1, 2, and 3 vacancies with hydrogen and passivating the 6-defect with oxygen turns on magnetism in the system. Due to structural distortion, the passivated defects do not have a well-ordered magnetic orientation. However, passivating the remaining defected structures maintains the nonmagnetic state. It is also shown that passivation leads to a semiconductor with a band gap value higher than that of the bare material. We also calculate the electronic and magnetic properties of transition metal (TM) atoms, including V, Cr, Mn, Fe, Co, Ni-adsorbed gt-C$_3$N$_4$ monolayer. All TM atoms show slight lattice distortion, and the adsorbed system almost maintains the original structure type. Moreover, a FM alignment was observed with a total magnetic moments of 2.89 $\mu_B$, 2 $\mu_B$, and 1 $\mu_B$ for V, Fe, and Co atoms, respectively. The Cr, Mn, and Ni atoms induce no magnetism to the non magnetic gt-C$_3$N$_4$ system.
使用密度泛函紧束缚方法（DFTB）和GFN1-xTB（几何结构、频率和非共价相互作用紧束缚）哈密顿量，我们研究了二维（2D）石墨碳氮化物（gt-C$_3$N$_4$）二维材料中的空位缺陷、氢和氧钝化缺陷以及铁吸附的结构、电子和磁性特性。 环状结构是最受欢迎的空位演化路径，半圆四重C-N-C-N空位具有显著的稳定性。 我们发现，原本无磁性的裸露gt-C$_3$N$_4$在创建2-和5-缺陷、缺陷的氢/氧钝化以及铁吸附后变得具有磁性。 有趣的是，铁原子与gt-C$_3$N$_4$薄片相互作用并导致基态铁磁（FM）状态。 此外，我们研究了在gt-C$_3$N$_4$上通过氢气钝化空位对其结构、电性和磁性的影响。 我们发现，将1、2和3号空位用氢取代，并用氧钝化6缺陷会使系统产生磁性。 由于结构畸变，钝化的缺陷没有良好的磁取向。 然而，钝化剩余的缺陷结构保持了非磁态。 还表明，钝化会导致带隙值高于原始材料的半导体。 我们还计算了过渡金属（TM）原子，包括V、Cr、Mn、Fe、Co、 Ni吸附在gt-C$_3$N$_4$单层上的电子和磁性性质。 所有TM原子均表现出轻微的晶格畸变，吸附系统几乎保持原来的结构类型。 此外，观察到FM排列，V、Fe和Co原子的总磁矩分别为2.89$\mu_B$、2$\mu_B$和1$\mu_B$。 Cr、Mn和Ni原子不会使非磁性的gt-C$_3$N$_4$系统产生磁性。
Cross submissions (showing 6 of 6 entries )
- [21] arXiv:2503.14406 (replaced) [cn-pdf, pdf, html, other]
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Title: Effects of time-periodic drive in the linear response for planar-Hall set-ups with Weyl and multi-Weyl semimetalsTitle: 周期性驱动对平面霍尔设置中Weyl和多Weyl半金属线性响应的影响Comments: this supersedes arXiv:2203.04281 [Physica E: Low-dimensional Systems and Nanostructures 144, 115444 (2022)], which has been withdrawn after numerous errors were identifiedSubjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
We investigate the influence of a time-periodic drive on three-dimensional Weyl and multi-Weyl semimetals in planar-Hall/planar-thermal-Hall set-ups. The drive is modelled here by circularly-polarized electromagnetic fields, whose effects are incorporated by a combination of the Floquet theorem and the van Vleck perturbation theory, applicable in the high-frequency limit. We evaluate the longitudinal and in-plane transverse components of the linear-response coefficients using the semiclassical Boltzmann formalism, thereby demonstrating the explicit analytical expressions of the conductivity for large frequencies. Our results corroborate the fact that the topological charges of the corresponding semimetals etch their trademark signatures in these transport properties, which can be detected in appropriate experiments.
我们研究了时间周期性驱动对平面霍尔/平面热霍尔设置中的三维外尔和多外尔半金属的影响。这里的驱动由圆偏振电磁场建模，其效果通过弗洛凯定理和范沃勒克微扰理论的结合来体现，在高频极限下适用。我们使用半经典玻尔兹曼形式主义评估线性响应系数的纵向和面内横向分量，从而展示了大频率下电导率的显式解析表达式。我们的结果证实了相应半金属的拓扑电荷在其输运性质中留下其标志性特征，这些特征可以在适当实验中检测到。
- [22] arXiv:2508.12280 (replaced) [cn-pdf, pdf, html, other]
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Title: Atom-surface interaction induced by quenched monopolar charge disorderTitle: 由淬火单极电荷无序引起的原子-表面相互作用Comments: 16 pages, 7 figures, 5 appendicesSubjects: Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ; Disordered Systems and Neural Networks (cond-mat.dis-nn) ; Materials Science (cond-mat.mtrl-sci) ; Atomic Physics (physics.atom-ph)
We study the modification to the energy level shifts of an atom induced by the quenched monopolar charge disorder inside the bulk of neighboring dielectric slabs as well as their surfaces. By assuming that the charge disorder follows Gaussian statistics with a zero mean, we find that the disorder generally results in a downward shift of the energy levels, which corresponds to an attractive force that can compete with and overcome the nonresonant Casimir-Polder force for sufficiently large atom-surface separations $z_0$. For an atom near a single semi-infinite slab with bulk (surface) charge disorder, the shift decays as $z_0^{-1}$ ($z_0^{-2}$). For both surface and bulk disorder, the shift is proportional to the variance of the charge disorder density. In addition, we investigate the behavior of the charge disorder-induced energy level shift for an atom confined to a vacuum gap between two coplanar and semi-infinite slabs of the same dielectric material, finding that the position of net zero disorder-induced force occurs closer to the surface of the slab with the smaller charge disorder variance.
我们研究了由邻近介电薄板内部及其表面的淬火单极电荷无序引起的原子能级偏移的修改。 通过假设电荷无序服从均值为零的高斯统计，我们发现无序通常会导致能级向下偏移，这对应于一种吸引力，对于足够大的原子-表面距离，该吸引力可以与非共振卡西米尔-波尔德力竞争并克服它$z_0$。 对于靠近单个半无限薄板且具有体（表面）电荷无序的原子，偏移量按$z_0^{-1}$（$z_0^{-2}$）衰减。 对于表面和体无序，偏移量与电荷无序密度的方差成正比。 此外，我们研究了当原子被限制在两个共面且半无限的相同介质薄板之间的真空间隙中时，由电荷无序引起的能级偏移行为，发现净无序引起的力的零点位置更接近电荷无序方差较小的薄板表面。
- [23] arXiv:2506.07789 (replaced) [cn-pdf, pdf, html, other]
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Title: Optical theorem and generalized energy conservation for scattering of time-modulated wavesTitle: 光学定理和调制波散射的广义能量守恒Comments: 24 pages, 5 figures. V2: added section VIISubjects: Optics (physics.optics) ; Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
We introduce and study a generalized energy conservation relation for scattering of time-modulated waves, where conventional energy conservation does not hold. Based on this relation, we derive an optical theorem and compute the active power describing the power input or output due to scattering. Notably, the same system may be subject to energy gain, energy loss, or energy conservation depending on the frequency harmonics present in the wave field. Moreover, we show how the optical theorem derived herein may be used for image reconstruction based on measurements of the power. In particular, such measurements do not require information about the phase of the scattered field.
我们引入并研究了时间调制波散射的广义能量守恒关系，其中传统能量守恒不成立。 基于此关系，我们推导出一个光学定理，并计算描述由于散射引起的功率输入或输出的有功功率。 值得注意的是，同一系统可能根据波场中存在的频率谐波而出现能量增益、能量损耗或能量守恒。 此外，我们展示了在此处推导的光学定理如何用于基于功率测量的图像重建。 特别是，此类测量不需要关于散射场相位的信息。
- [24] arXiv:2508.11586 (replaced) [cn-pdf, pdf, html, other]
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Title: Measuring irreversibility by counting: a random coarse-graining frameworkTitle: 通过计数测量不可逆性：一种随机粗粒化框架Comments: 5+3 pages, 2 figures, some typos are corrected, Fig. 2 has been replacedSubjects: Statistical Mechanics (cond-mat.stat-mech) ; Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ; Soft Condensed Matter (cond-mat.soft) ; Biological Physics (physics.bio-ph)
Thermodynamic irreversibility is a fundamental concept in statistical physics, yet its experimental measurement remains challenging, especially for complex systems. We introduce a novel random coarse-graining framework to identify model-free measures of irreversibility in complex many-body systems. These measures are constructed from the asymmetry of cross-correlation functions between suitably chosen observables, providing rigorous lower bounds on entropy production. For many-particle systems, we propose a particularly practical implementation that divides real space into virtual boxes and monitors particle number densities within them, requiring only simple counting from video microscopy, without single-particle tracking, trajectory reconstruction, or prior knowledge of interactions. Owing to its generality and minimal data requirements, the random coarse-graining framework offers broad applicability across diverse nonequilibrium systems.
热力学不可逆性是统计物理中的一个基本概念，但其实验测量仍然具有挑战性，尤其是在复杂系统中。 我们引入了一种新颖的随机粗粒化框架，以在复杂多体系统中识别模型无关的不可逆性度量。 这些度量是从适当选择的可观测量之间的交叉相关函数的不对称性构建的，提供了熵产生的严格下限。 对于多粒子系统，我们提出了一种特别实用的实现方法，将真实空间划分为虚拟盒子，并监测其中的粒子数密度，只需要从视频显微镜中进行简单的计数，而无需单粒子追踪、轨迹重建或对相互作用的先验知识。 由于其普遍性和最小的数据需求，随机粗粒化框架在各种非平衡系统中具有广泛的应用前景。