中尺度与纳米尺度物理
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- [1] arXiv:2510.17982 [中文pdf, pdf, 其他]
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标题： 噪声与库容量引起的退相干在持续电流中的相互作用标题： Interplay of Noise and Reservoir-induced Decoherence in Persistent Currents评论： 7+4页，4图主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 量子气体 (cond-mat.quant-gas) ; 统计力学 (cond-mat.stat-mech) ; 量子物理 (quant-ph)
持久电流是量子相位相干的标志。 我们在非平衡条件下研究持久电流的命运，其中紧束缚环受到随机无序的影响，并且每个站点都连接着费米子库。 我们使用Keldysh技术计算电流，发现它表现出非单调行为，表明存在两种不同的退相干机制。 虽然与库的耦合引入了一个由耦合强度倒数给出的相干长度尺度，但另一种机制更为微妙，由噪声强度与库耦合的比值驱动。 噪声与库的相互作用构成了一种纯粹的非平衡稳态，其分布函数更平坦，我们有效地通过经典速率方程来描述它。 我们讨论了在超冷原子实验中实现我们发现的可能性。
Persistent current is a hallmark of quantum phase coherence. We study the fate of the persistent current in a non-equilibrium setting, where a tight-binding ring is subjected to stochastic disorder as well as a fermionic reservoir attached to each site. We evaluate the current using Keldysh technique and find that it exhibits non-monotonic behavior, suggesting two distinct mechanisms of decoherence. While coupling to the reservoirs introduces a coherence length scale given by the inverse of the coupling strength, the other mechanism is more subtle and driven by the ratio of noise strength to reservoir coupling. The interplay of noise and reservoir constitutes a purely non-equilibrium steady state with a flatter distribution function that we effectively describe using classical rate equations. We discuss possibilities of realizing our findings in ultracold-atom experiments.
- [2] arXiv:2510.18001 [中文pdf, pdf, html, 其他]
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标题： 磁旋子系统中的磁感应磁二极管效应标题： Magnus Induced Magnetic Diode Effect in Skyrmion Systems评论： 7页，10图主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall)
我们证明了自旋涡可以表现出我们所谓的磁二极管效应，当磁场反转时，在传输中存在非互易响应。 这种效应可以通过自旋涡在一边具有锯齿势、另一边具有相反锯齿势的通道中移动来实现。 我们考虑了自旋转移扭矩（STT）和自旋轨道扭矩（SOT）驱动的情况。 当磁场保持固定时，对于STT和SOT驱动，电流在任一方向施加时自旋涡的速度响应相同，因此没有电流二极管效应。 当磁场反转时，在STT驱动下，自旋涡的速度会反转且绝对值发生变化。 在SOT驱动下，速度方向保持不变但下降到一个更低的值，导致负微分电导。 对于固定的电流，我们发现自旋涡的速度作为正负外加场的函数呈现非互易性，类似于通常二极管效应中观察到的速度-电流曲线。 非互易性是由马格努斯力产生的，该力使自旋涡优先与通道的一侧相互作用。 由于通道两侧具有相反的不对称性，正磁场可以使自旋涡与通道的“硬”不对称侧相互作用，而负磁场则使其与“易”不对称侧相互作用。 这种几何结构可用于创建新型的磁场诱导二极管效应，并可在新型自旋涡基器件中加以利用。
We show that skyrmions can exhibit what we call a magnetic diode effect, where there is a nonreciprocal response in the transport when the magnetic field is reversed. This effect can be achieved for skyrmions moving in a channel with a sawtooth potential on one side and a reversed sawtooth potential on the other side. We consider the cases of both spin-transfer torque (STT) and spin-orbit torque (SOT) driving. When the magnetic field is held fixed, the velocity response of the skyrmion is the same for current applied in either direction for both STT and SOT driving, so there is no current diode effect. When the magnetic field is reversed, under STT driving the velocity of the skyrmion reverses and its absolute value changes. Under SOT driving, the velocity remains in the same direction but drops to a much lower value, resulting in negative differential conductivity. For a fixed current, we find a nonreciprocal skyrmion velocity as a function of positive and negative applied fields, in analogy to the velocity-current curves observed in the usual diode effect. The nonreciprocity is generated by the Magnus force, which causes skyrmions to interact preferentially with one side of the channel. Since the channel sides have opposite asymmetry, a positive magnetic field can cause the skyrmion to interact with the "hard" asymmetry side of the channel, while a negative magnetic field causes the skyrmion to interact with the easy asymmetry side. This geometry could be used to create new kinds of magnetic-field-induced diode effects that can be harnessed in new types of skyrmion-based devices.
- [3] arXiv:2510.18092 [中文pdf, pdf, html, 其他]
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标题： 通过磁振子相互作用的Skyrmion霍尔粘度标题： A Hall viscosity for skyrmion via magnon interaction评论： 5+5页，含2个图主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 材料科学 (cond-mat.mtrl-sci) ; 高能物理 - 理论 (hep-th)
我们通过时间平均磁振子贡献到所有阶次，直接从Dzyaloshinskii-Moriya相互作用（DMI）中识别出一个霍尔粘度项，该相互作用破坏了宇称对称性，在绝缘磁体的磁畴运动中。 该粘度项与磁畴电荷成正比。 磁畴霍尔角度对磁畴形状和大小、交换参数与DMI参数的比率有显著依赖关系，而大致与Gilbert阻尼参数无关。 相反磁畴电荷的霍尔角度具有相同的大小。 我们推测存在一个与速度相关的霍尔粘度贡献，以寻求相反电荷的不对称霍尔角度。
We identify a Hall viscosity term directly from the Dzyaloshinskii-Moriya interaction (DMI), that breaks parity symmetry, in the skyrmion motion of insulating magnets by time-averaging the magnon contribution to all orders. The viscosity term is proportional to the skyrmion charge. Skyrmion Hall angle shows significant dependence on the skyrmion shape and size, the ratio of exchange over DMI parameters, while roughly independent of the Gilbert damping parameter. The Hall angles have the same magnitude for opposite skyrmion charges. We speculate a velocity-dependent Hall viscosity contribution to seek asymmetric Hall angles for the opposite charges.
- [4] arXiv:2510.18145 [中文pdf, pdf, html, 其他]
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标题： Altermon：基于窄交替磁体约瑟夫森结的无磁场宇称保护量子比特标题： Altermon: a magnetic-field-free parity protected qubit based on a narrow altermagnet Josephson junction主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 超导性 (cond-mat.supr-con)
自旋轨道磁体为在无磁场的情况下设计超导电路提供了一条新途径。 我们理论研究了基于自旋轨道磁体的有限宽度约瑟夫森结的安德列夫束缚态（ABS）谱，并展示了$d$波自旋轨道磁体对称性和几何限制如何塑造其低能激发。 我们发现两种$d$波对称性之间存在明显区别： $d_{x^2-y^2}$对称性产生自旋分裂，而$d_{xy}$对称性保持自旋简并，并表现出由模间混合引起的ABS谱分裂。 利用这些新特性，我们提出应用横向电场来调节系统，实现一种无需磁场、受宇称保护的超导量子比特，我们称之为自旋轨道量子比特。
Altermagnets provide a new route to engineer superconducting circuits without magnetic fields. We theoretically study the Andreev bound state (ABS) spectrum of a finite-width altrmagnet-based Josephson junction and show how the $d$-wave altermagnetic symmetry and geometric confinement shape its low-energy excitations. We find a clear distinction between the two $d$-wave symmetries: $d_{x^2-y^2}$ order produces spin splitting, whereas $d_{xy}$ order preserves spin degeneracy and exhibits splitting of the ABS spectrum induced by intermode hybridization. Leveraging these novel features, we propose applying a transverse electric field to tune the system and realize a magnetic-field-free, parity-protected superconducting qubit that we call altermon.
- [5] arXiv:2510.18272 [中文pdf, pdf, 其他]
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标题： 所有电自切换范德华手性反铁磁体标题： All-Electrical Self-Switching of van der Waals Chiral AntiferromagnetJunlin Xiong, Jiawei Jiang, Yanwei Cui, Han Gao, Ji Zhou, Zijia Liu, KuiKui Zhang, Shaobo Cheng, Kehui Wu, Sang-Wook Cheong, Kai Chang, Zhongkai Liu, Hongxin Yang, Shi-Jun Liang, Bin Cheng, Feng Miao主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 材料科学 (cond-mat.mtrl-sci)
反铁磁体由于其微弱的漏磁场和超快的磁动力学特性，引起了广泛关注，这使其在高密度和超快自旋电子学应用中具有前景。 它们作为自旋源和信息载体的双重功能，可能实现反铁磁序的全电气自激发切换，为超紧凑的自旋电子器件提供了巨大潜力。 然而，相关进展仍然难以捉摸。 在此，我们报告了在范德华（vdW）磁性插层过渡金属二硫化物CoTa3S6中，零外加磁场下由电荷电流引起的手性反铁磁序的确定性切换。 该系统表现出钴原子磁矩晶格与金属层中巡游电子之间的强相互作用，这通过温度依赖的角度分辨光电子能谱、扫描隧道谱以及拓扑能斯特效应测量得到了证实。 值得注意的是，巡游-局域相互作用导致了电流诱导的手性自旋轨道扭矩以及与局域磁矩相互作用的Ruderman-Kittel-Kasuya-Yosida（RKKY）交换扭矩，促进了CoTa3S6薄片中手性磁序的全电气切换。 我们的工作为通过精心设计磁矩与巡游电子之间的协同相互作用来操控反铁磁序开辟了一条有前途的途径。
Antiferromagnets have garnered significant attention due to their negligible stray field and ultrafast magnetic dynamics, which are promising for high-density and ultrafast spintronic applications. Their dual functionality as both spin sources and information carriers could enable all-electrical self-induced switching of antiferromagnetic order, offering great potential for ultra-compact spintronic devices. However, related progress is still elusive. Here, we report the deterministic switching of chiral antiferromagnetic orders induced by charge current at zero external magnetic field in the van der Waals (vdW) magnetically intercalated transition metal dichalcogenide CoTa3S6. This system exhibits strong interactions between cobalt atom magnetic moment lattice and itinerant electrons within the metallic layers, as demonstrated by temperature-dependent angle-resolved photoemission, scanning tunneling spectroscopy, and topological Nernst effect measurements. Notably, the itinerant-localization interactions lead to current-induced chiral spin orbit torques as well as Ruderman-Kittel-Kasuya-Yosida (RKKY) exchange torques that interact with the localized magnetic moments, facilitating all-electrical switching of the chiral magnetic order in the CoTa3S6 flake. Our work opens a promising avenue for manipulating antiferromagnetic orders by delicately engineering the synergistic interactions between magnetic moments and itinerant electrons.
- [6] arXiv:2510.18275 [中文pdf, pdf, 其他]
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标题： 过渡金属二硫化物纳米带中的自旋间隙与原子吸附物标题： Spin gaps in Transition Metal Dichalcogenide Nanoribbons with atomic Adsorbates主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall)
边缘功能化的锯齿形过渡金属二硫属化物纳米带（zTMDCNRs）在自旋传输特性方面进行了研究。 具体而言，涉及五排zWXY单元的系统类型5-zWXYNR + nA（X，Y = S，Se；n = 0，1，2；A = H，B，C，N，O）被作为介于无限电极之间的传输元件进行研究，以确定原子吸附物及其吸附条件，从而最大化通过纳米带的电流的自旋极化。 这些单元的Janus对应物，即由两种不同的硫属元素层夹着一个过渡金属层的不对称结构，也包含在本研究中。 在所有考虑的情况下，密度泛函理论（DFT）建模结合了非平衡格林函数（NEGF）方法，使用混合Heyd-Scuseria-Ernzerhof（HSE）交换相关泛函，以确定自旋和电荷输运特性。 评估了所选原子吸附物对5-zWXYNR（X，Y = S，Se）的几何、电子和磁性特性的影响。 根据相应电极单元的能带结构分析，制定了一种评估5-zWXYNR + nad的自旋过滤能力的协议，该能力取决于原子吸附物的性质和密度。 显示靠近电极费米能级出现的自旋能隙可有效预测所研究的任何传输系统实现的电流自旋极化程度。 对于任何考虑的吸附物配置，均检查了铁磁（FM）和反铁磁（AFM）排列，并讨论了磁相位对自旋输运特性的影响。 识别出特定纳米带系统中的自旋选择性负微分电阻效应。
Edge-functionalized Transition Metal dichalcogenide nanoribbons of the zigzag type (zTMDCNRs) are explored in terms of their spin transmission properties. Specifically, systems of the type 5-zWXYNR + nA (X, Y = S, Se; n = 0, 1, 2; A = H, B, C, N, O), involving five rows of a zWXY unit, are investigated as transmission elements between semi-infinite electrodes, to identify atomic adsorbates and adsorption conditions for maximizing the spin polarization of current traversing the ribbons. Janus counterparts of these units, asymmetric structures comprising a transition metal layer sandwiched by two different chalcogen layers, are included in this study. In all cases considered, density functional theory (DFT) modeling, involving the hybrid Heyd-Scuseria-Ernzerhof (HSE) exchange-correlation functional, is combined with the non-equilibrium Green's function (NEGF) approach to determine both spin and charge transport properties. The effect of the selected atomic absorbates on the geometric, electronic, and magnetic properties of 5-zWXYNR (X, Y = S, Se) is evaluated. A protocol to assess the spin-filtering capacity of 5-zWXYNR + nad as a function of the nature and the density of atomic adsorbates, is formulated in terms of band structure analysis of the respective electrode units. Spin gaps emerging close to the Fermi energy of the electrode are shown to provide an effective predictor for the degree of current spin polarization achieved by any of the transmission systems studied here. For any adsorbate configuration considered, ferromagnetic (FM) as well as antiferromagnetic (AFM) ordering is examined, and the impact of the magnetic phase on the spin transport properties is discussed. A spin-selective negative differential resistance effect is identified for specific nanoribbon systems.
- [7] arXiv:2510.18482 [中文pdf, pdf, html, 其他]
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标题： 范德华碳炔晶体中的半导体-半金属转变标题： Semiconductor-Semimetal Transition in van der Waals Carbyne Crystals主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall)
由单原子碳链（碳炔）组成的独立范德华晶体最近在技术上已经实现。 在这里，我们通过连续波和时间分辨光致发光光谱实验研究了它们的电子和光学性质，并进行了理论研究。 采用一种完全三维的紧束缚形式，该形式经过密度泛函理论计算的验证，我们预测在由约42个原子长的链组成的范德华碳炔晶体中会发生半金属性-半导体转变。 半导体相的特点是具有双曲型van Hove奇点，这导致了非常规的双曲激子态。 实验上，我们进入了半导体相，其中与双曲激子相关的共振特征清晰可见。 发现激子振子强度对碳链长度非常敏感：我们的实验表明，随着链长的增加，激子振子强度会下降。 这一趋势通过理论模型得到了确认，它表现出在向半导体-半金属转变过程中双曲激子态的演化。 我们的方法考虑了实际的晶体几何结构，包括链内交替跳跃和链间耦合。 通过将紧束缚色散拟合到密度泛函理论数据，我们提取了参数并建立了全面的碳炔晶体物理框架。 这项研究为在终极一维碳晶体中高效带隙工程铺平了道路。
Freestanding van der Waals crystals made of single-atom carbon chains (car- bynes) have been recently realized technologically. Here we investigate their electronic and optical properties experimentally, by continuous-wave and time- resolved photoluminescence spectroscopy, and theoretically. Employing a fully three-dimensional tight-binding formalism benchmarked against density func- tional theory calculations we predict the semimetal-semiconductor transition to occur in van der Waals carbyne crystals composed by the chains of about 42 atoms long. The semiconductor phase is characterized by a hyperbolic van Hove singularity which gives rise to unconventional hyperbolic exciton states. Experi- mentally, we access the semiconductor phase, where resonant features associated with hyperbolic excitons are clearly visible. The exciton oscillator strength is found to be strongly sensitive to the length of carbon chains: our experiments show that it decreases with the increasing chain length. This tendency, con- firmed by the theoretical modeling, manifests the evolution of the hyperbolic exciton state on the way to the semiconductor-semimetal crossover. Our approach accounts for the actual crystalline geometry, including alternating intra-chain hoppings and inter-chain couplings. By fitting tight-binding dispersions to density functional theory data we extract consistent parameters and establish a com- prehensive framework for the physics of carbyne crystals. This study paves the way towards efficient band-gap engineering in ultimate one-dimensional carbon crystals.
- [8] arXiv:2510.18532 [中文pdf, pdf, html, 其他]
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标题： 基于长程Su-Schrieffer-Heeger链的斐波那契工程自旋和电荷热电性：实现巨大优值的途径标题： Fibonacci-Engineered Spin and Charge Thermoelectrics in a Long Range Su-Schrieffer-Heeger Chain: A Pathway to Giant Figure of Merit评论： 17页，18图，已被《应用物理杂志》接受主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall)
在本工作中，我们对扩展的Su-Schrieffer-Heeger（SSH）模型的自旋依赖热电性能进行了新颖的研究，首次展示了其内在自旋过滤机制如何被战略性地利用，作为高效的自旋热电发电机。 通过在局域能级中引入类似斐波那契的非周期调制，我们设计了一种确定性无序，模拟了现实中的非周期系统，并深刻影响了输运特性。 此外，我们结合了具有可调余弦依赖性的最近邻（NN）和次近邻（NNN）跃迁幅度，使我们能够细致地探索这些跃迁过程之间的复杂相互作用及其对热电行为的影响。 我们的分析显示，在精心优化的条件下，电荷和自旋传输通道的无量纲热电优值ZT显著增强。 值得注意的是，自旋热电响应表现出明显的优势，为下一代热电材料和器件的设计开辟了新的领域。 这项定性研究不仅加深了我们对非周期拓扑系统的理解，还建立了一个基础框架，用于在低维平台中开发基于自旋的热电效应。
In this work, we present a novel investigation into the spin-dependent thermoelectric performance of an extended Su-Schrieffer-Heeger (SSH) model, showcasing for the first time how its intrinsic spin filtration mechanism can be strategically harnessed to function as an efficient spin thermoelectric generator. By introducing a Fibonacci-type aperiodic modulation in the onsite energies, we engineer a deterministic disorder that mimics realistic aperiodic systems and profoundly influences transport characteristics. Furthermore, we incorporate both nearest-neighbor (NN) and next-nearest-neighbor (NNN) hopping amplitudes with tunable cosine dependencies, enabling us to meticulously explore the intricate interplay between these hopping processes and its implications on thermoelectric behavior. Our analysis reveals a remarkable enhancement in the dimensionless thermoelectric figure of merit ZT for both charge and spin transport channels, under carefully optimized conditions. Notably, the spin thermoelectric response exhibits distinct advantages, opening a new frontier in the design of next-generation thermoelectric materials and devices. This qualitative study not only deepens our understanding of aperiodic topological systems but also establish a foundational framework for exploiting spin-based thermoelectricity in low-dimensional platforms.
- [9] arXiv:2510.18613 [中文pdf, pdf, html, 其他]
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标题： 用动态杂质层析术学习哈密顿量的量子磁体标题： Hamiltonian learning quantum magnets with dynamical impurity tomography评论： 10页，5图主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 强关联电子 (cond-mat.str-el)
纳米尺度工程自旋系统，从表面自旋到纳米石墨烯，提供了从下而上的方法实现纠缠量子磁体的灵活平台。 然而，由于难以分离解释多体激发的竞争项，评估特定实验中实现的量子多体哈密顿量仍然是一个特殊的开放挑战。 在这里，我们展示了一种机器学习策略，从自旋激发的扫描光谱测量中学习量子多体自旋哈密顿量。 我们的方法利用了在量子磁体旁边沉积量子杂质引起的多体激发的空间分辨重建。 我们证明，我们的算法允许我们预测长程海森堡交换相互作用、各向异性交换以及反对称的Dzyaloshinskii-Moriya相互作用，即使在存在显著噪声的情况下也是如此。 我们的方法确立了量子磁体中缺陷诱导的空间分辨动态激发作为一种强大的策略，以理解量子自旋多体模型的本质。
Nanoscale engineered spin systems, ranging from spins on surfaces to nanographenes, provide flexible platforms to realize entangled quantum magnets from a bottom up approach. However, assessing the quantum many-body Hamiltonian realized in a specific experiment remains an exceptional open challenge, due to the difficulty of disentangling competing terms accounting for the many-body excitations. Here, we demonstrate a machine learning strategy to learn a quantum many-body spin Hamiltonian from scanning spectroscopy measurements of spin excitations. Our methodology leverages the spatially-resolved reconstruction of the many-body excitations induced by depositing quantum impurities next to the quantum magnet. We demonstrate that our algorithm allows us to predict long-range Heisenberg exchange interactions, anisotropic exchange, as well as antisymmetric Dzyaloshinskii-Moriya interaction, including in the presence of sizable noise. Our methodology establishes defect-induced spatially-resolved dynamical excitations in quantum magnets as a powerful strategy to understand the nature of quantum spin many-body models.
- [10] arXiv:2510.18665 [中文pdf, pdf, html, 其他]
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标题： 磁等离子体模式通过与亚带间极化子耦合的腔体修改标题： Cavity modification of magnetoplasmon mode through coupling with intersubband polaritonsLucy L. Hale, Daniele De Bernardis, Stephan Lempereur, Lianhe H. Li, A. Giles Davies, Edmund H. Linfield, Trevor Blaikie, Chris Deimert, Zbigniew R. Wasilewski, Iacopo Carusotto, Jean-Michel Manceau, Mathieu Jeannin, Raffaele Colombelli, Jérôme Faist, Giacomo Scalari主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 材料科学 (cond-mat.mtrl-sci)
我们研究了多模金属-绝缘体-金属腔在强磁场存在的情况下与量子阱中二维电子气(2DEG)的耦合。 TM腔模式与2DEG的子带间跃迁强烈混合，形成超强耦合 regime 中的极化子模式，而TE模式则几乎保持为纯腔模式。 由磁场存在产生的磁等离子体激发与TM和TE模式耦合，表现出不同的耦合强度和空间场不均匀性水平。 虽然裸TE模式的强均匀性导致了强耦合的标准反交叉，但非均匀的极化子TM模式被证明在光谱响应中激活了可观测的库仑效应，通常称为非局域性。 该实验展示了腔诱导的2DEG响应的修改，并通过重塑其腔模式轮廓提供了一种新的方法来探测超强耦合系统中库仑相互作用的影响。
We investigate the coupling of a multi-mode metal-insulator-metal cavity to a two-dimensional electron gas (2DEG) in a quantum well in the presence of a strong magnetic field. The TM cavity mode is strongly hybridized with an intersubband transition of the 2DEG, forming a polaritonic mode in the ultrastrong coupling regime, while the TE mode remains an almost purely cavity mode. The magnetoplasmon excitation emerging from the presence of the magnetic field couples with both TM and TE modes, exhibiting different coupling strengths and levels of spatial field inhomogeneity. While the strong homogeneity of the bare TE mode gives rise to the standard anticrossing of strong coupling, the inhomogeneous polaritonic TM mode is shown to activate an observable Coulombic effect in the spectral response, often referred to as non-locality. This experiment demonstrates a cavity-induced modification of the 2DEG response and offers a new route to probing the effect of Coulomb interactions in ultrastrongly coupled systems via reshaping of their cavity mode profiles.
- [11] arXiv:2510.18694 [中文pdf, pdf, html, 其他]
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标题： 异质双层薄片中莫尔扭曲角的几何控制标题： Geometric control of the moire twist angle in heterobilayer flakes评论： 8页，5图主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall)
我们展示了一种在晶格失配的二维异质双层材料中的有限扭转角稳定机制，这是由于晶片边缘与其莫尔条纹之间的几何对齐所导致的。 通过直径高达$\sim 2500${\AA } 的石墨烯在六方氮化硼晶片上的原子级模拟，我们确定了扶手椅形边缘晶片的稳定亚稳角度为$\sim 0.61^\circ$和锯齿形边缘晶片的稳定亚稳角度为$\sim1.89^\circ$，这些角度可通过面内异质应变进行调节。 这种锁定机制依赖于比附近亚稳扭转角的能量势垒大一个数量级的势垒，为二维异质结构的精确扭转角控制提供了一种几何途径，并有助于理解宏观晶片的自定向。
We demonstrate a finite twist-angle stabilization mechanism in lattice-mismatched 2D heterobilayers, which results from the geometric alignment between the flake edges and its moire pattern. Using atomistic simulations of graphene on hexagonal boron nitride flakes with diameters of up to $\sim 2500${\AA}, we identify robust metastable angles at $\sim 0.61^\circ$ for armchair and $\sim1.89^\circ$ for zigzag-edged flakes, tunable via in-plane heterostrain. This locking mechanism, which relies on energy barriers that are an order of magnitude larger than those of nearby metastable twist angles, provides a geometric route to precision twist-angle control of two-dimensional heterostructures and to understand the self-orientation of macroscopic flakes.
- [12] arXiv:2510.18717 [中文pdf, pdf, html, 其他]
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标题： CdSe、CdS 和 CdTe 纳米片在溶液中的消光系数：浓度测定的实用工具标题： Extinction Coefficients of CdSe, CdS, and CdTe Nanoplatelets in Solution: A Practical Tool for Concentration DeterminationMichael H. Stewart, Michael W. Swift, Farwa Awan, Liam Burke, Christopher M. Green, Barbara A. Marcheschi, Igor L. Medintz, Todd D. Krauss, Alexander L. Efros评论： 13页，3图。补充信息：12页，3图主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 光学 (physics.optics)
半导体纳米板具有优异的光学特性，使其成为下一代光电子应用的有前途的候选材料。 然而，与量子点不同，仅通过吸收光谱即可确定其尺寸和浓度，而纳米板则面临显著的表征挑战：吸收峰位置仅能揭示厚度，无法提供关于横向尺寸或浓度的信息。 这一限制迫使研究人员依赖耗时且昂贵的元素分析技术来进行完整的样品表征。 在此，我们提出了一种经过实验验证的理论框架，可预测随机取向的CdSe、CddS和CdTe纳米板的频率依赖吸收系数，从而能够从吸收测量中确定浓度并估算横向尺寸。 我们的模型表明，积分吸收系数普遍依赖于纳米板的表面积和厚度，提供了一种实用工具，可在无需繁琐元素分析的情况下提取浓度。 这种方法弥合了量子点和纳米板之间的表征差距，提供了一种简化的快速样品分析方法，可能加速纳米板的研究和应用。
Semiconductor nanoplatelets possess exceptional optical properties that make them promising candidates for next-generation optoelectronic applications. However, unlike quantum dots where absorption spectroscopy alone can determine both size and concentration, nanoplatelets present a significant characterization challenge: the absorption peak position reveals only thickness, providing no information about lateral dimensions or concentration. This limitation forces researchers to rely on time-consuming and costly elemental analysis techniques for complete sample characterization. Here, we present an experimentally verified theoretical framework that predicts the frequency-dependent absorption coefficient of randomly oriented CdSe, CdS, and CdTe nanoplatelets, enabling concentration determination from absorption measurements and lateral size estimates. Our model shows that the integrated absorption coefficient depends universally on nanoplatelet surface area and thickness, yielding a practical tool to extract concentrations without laborious elemental analysis. This approach bridges the characterization gap between quantum dots and nanoplatelets, offering a streamlined method for rapid sample analysis that could accelerate nanoplatelet research and applications.
- [13] arXiv:2510.18778 [中文pdf, pdf, html, 其他]
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标题： 用于窄带、断裂带和反向带（拓扑）异质结构栅极控制的自洽模型标题： Self-Consistent Model for Gate Control of Narrow-, Broken-, and Inverted-Gap (Topological) HeterostructuresMaximilian Hofer, Christopher Fuchs, Moritz Siebert, Christian Berger, Lena Fürst, Martin Stehno, Steffen Schreyeck, Hartmut Buhmann, Tobias Kießling, Wouter Beugeling, Laurens W. Molenkamp主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 计算物理 (physics.comp-ph)
即使微小的静电势也能显著影响窄带、断裂带和反向带隙材料的能带结构。 定量理解通常需要自洽的哈特里方法。 价带和导带状态在这些系统中强烈杂化和/或交叉。 这使得区分电子和空穴变得不可能，且在电荷中性点假设平坦的载流子分布难以成立。 因此，宽带方法在这些系统中通常失效。 另一种方法是 Andlauer 和 Vogl 提出的全带包络函数方法，该方法已集成到开源软件包 kdotpy（arXiv:2407.12651）中。 我们展示该方法和实现能够在传统方法失效的情况下，通过建模厚（26 nm - 110 nm）、拓扑反转的 HgTe 量子阱中的顶部栅压实验子带密度演化，得到数值稳定且定量准确的结果。 我们期望我们公开可用的实现将极大地促进窄带、断裂带和反向带隙材料的研究。
Even small electrostatic potentials can dramatically influence the band structure of narrow-, broken-, and inverted-gap materials. A quantitative understanding often necessitates a self-consistent Hartree approach. The valence and conduction band states strongly hybridize and/or cross in these systems. This makes distinguishing between electrons and holes impossible and the assumption of a flat charge carrier distribution at the charge neutrality point hard to justify. Consequently the wide-gap approach often fails in these systems. An alternative is the full-band envelope-function approach by Andlauer and Vogl, which has been implemented into the open-source software package kdotpy (arXiv:2407.12651). We show that this approach and implementation gives numerically stable and quantitatively accurate results where the conventional method fails by modeling the experimental subband density evolution with top-gate voltage in thick (26 nm - 110 nm), topologically inverted HgTe quantum wells. We expect our openly-available implementation to greatly benefit the investigation of narrow-, broken-, and inverted-gap materials.
- [14] arXiv:2510.18785 [中文pdf, pdf, html, 其他]
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标题： 通用节点点的费米弧，其携带单极子或偶极子标题： Fermi arcs for generic nodal points hosting monopoles or dipoles评论： 14页，6图主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 高能物理 - 理论 (hep-th)
费米弧代表三维拓扑半金属与真空边界处的表面态，展示了体-边界对应关系在实际材料中的体现。 它们的特殊性质与半金属动量空间中节点所携带的拓扑电荷有关，其中两个或多个能带相交。 事实上，它们被限制在能带费米面投影的边缘上开始和结束，表明它们与体态混合。 围绕给定节点的最外层投影切线处的费米弧数量也反映了该节点处电荷的大小（等于贝里曲率单极子），揭示了底层能带结构的内在拓扑性，这可以在像角分辨光电子能谱（ARPES）这样的实验中观察到。 在这里，我们承担了明确表征这些状态解析结构的任务，针对一般的节点点，(1) 其简并可能是二重或多重的；(2) 相关能带可能表现出各向同性或各向异性、动量线性或非线性色散。 此外，我们还探讨了这样一个问题：对于携带单极子为零值但代表理想偶极子的拓扑节点，是否应该出现任何费米弧。
Fermi arcs represent the surface states at the boundary of a three-dimensional topological semimetal with the vacuum, illustrating the notion of bulk-boundary correspondence playing out in real materials. Their special character is tied up with the topological charges carried by the nodes of the semimetal in the momentum space, where two or more bands cross. In fact, they are constrained to begin and end on the perimeters of the projections of the Fermi surfaces of the bands tangentially, signalling their mixing with the bulk states. The number of Fermi arcs grazing onto the tangents of the outermost projection about a given node also reflects the magnitude of the charge at the node (equalling the Berry-curvature monopole), revealing the intrinsic topology of the underlying bandstructure, which can be visualised in experiments like ARPES. Here we take upon the task of unambiguously characterising the analytical structure of these states for generic nodal points, (1) whose degeneracy might be twofold or multifold; and (2) the associated bands might exhibit isotropic or anisotropic, linear- or nonlinear-in-momentum dispersion. Moreover, we also address the question of whether we should get any Fermi arcs at all for topological nodes carrying zero values of monopoles, but representing ideal dipoles.
新提交 (展示 14 之 14 条目 )
- [15] arXiv:2510.17827 (交叉列表自 physics.optics) [中文pdf, pdf, 其他]
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标题： 太赫兹频段使用AlGaN/GaN等离子体晶体的频率倍增标题： Frequency multiplication in Terahertz band using AlGaN/GaN plasmonic crystals评论： 11页，7图主题： 光学 (physics.optics) ; 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 应用物理 (physics.app-ph)
等离子体振荡在高迁移率场效应晶体管（HEMTs）中已成为在亚太赫兹（sub-THz）和太赫兹（THz）频率范围操控电磁辐射的关键物理机制。 这些集体电子激发可以通过电气方式激发和调节，为一系列下一代技术的紧凑、可集成组件提供有吸引力的途径，包括第六代（6G）无线网络、高分辨率生物医学和化学光谱学、工业过程监测以及先进的安全和防御系统。 对于这些应用，等离激子晶体——许多强耦合FET通道的周期性阵列——特别有前景。 在本工作中，我们报告了一类在等离激子晶体中出现的新型集体激发，称为旋子等离激子，它们在等离激子模式交叉处出现，并表现出类似于软模和旋子样光谱的抛物线色散规律。 我们表明，在等离激子晶体单元细胞上的均匀栅极调制会引起片状载流子浓度的周期性变化，从而导致等离子体频率的变化。 这种时间周期性调制驱动非线性等离激子参数共振，实现射频到太赫兹的转换。 通过求解带有阻尼的广义马蒂厄方程，我们证明高幅值栅极泵浦可以实现频率倍增，并且在低温温度（77K）下由于电子迁移率增强会导致参数不稳定性。 在低迁移率的等离激子晶体中，射频到太赫兹的转换可以通过周期性短脉冲激励实现，我们将其引入为时域频率乘法（TDFM）。 对AlGaN/GaN低-高等离激子晶体的研究证实了它们作为可调谐、紧凑太赫兹源的潜力。
The plasma oscillations in high-mobility field-effect transistors (HEMTs) have emerged as a key physical mechanism for manipulating electromagnetic radiation in the sub-terahertz (sub-THz) and THz frequency ranges. These collective electron excitations can be excited and tuned electrically offering a compelling route to compact, integrable components for a wide range of next-generation technologies, including sixth-generation (6G) wireless networks, high-resolution biomedical and chemical spectroscopy, industrial process monitoring, and advanced security and defense systems. For these applications, plasmonic crystals -- periodic arrays of many strongly coupled FET channels-- are particularly promising. In this work, we report on a new class of collective excitations in plasmonic crystals termed rotonic plasmons, which arise at plasmonic mode crossings and exhibit a parabolic dispersion law reminiscent of soft-mode and roton-like spectra. We show that uniform gate modulation across plasmonic crystal unit cells induces periodic variations in the sheet carrier concentration and, consequently, in the plasma frequency. This time-periodic modulation drives nonlinear plasmonic parametric resonances enabling RF-to-THz conversion. By solving the generalized Mathieu equation with damping, we demonstrate that high-amplitude gate pumping enables frequency multiplication and, at cryogenic temperatures (77K) leads to parametric instabilities due to enhanced electron mobility. In plasmonic crystals with lower mobility, RF-to-THz conversion can instead be realized via periodic short-pulse excitation, a regime we introduce as Time-Domain Frequency Multiplication (TDFM). Investigation of AlGaN/GaN low-high plasmonic crystals confirm their potential as tunable, compact THz sources.
- [16] arXiv:2510.18209 (交叉列表自 cond-mat.str-el) [中文pdf, pdf, html, 其他]
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标题： 手性/轴性诱导的轴性/手性通过表面极化标题： Chirality/Axiality-Induced Axiality/Chirality via Surface Polarization评论： 6页，4图，已接受发表于《J. Phys. Soc. Jpn》主题： 强关联电子 (cond-mat.str-el) ; 中尺度与纳米尺度物理 (cond-mat.mes-hall)
在凝聚态物理中，诸如手性、轴性以及极性等广泛的物理特性是系统基本对称性的直接结果。 我们在此理论研究手性与轴性在其畴边界处通过极性介导的有效耦合。 基于对称性考虑和模型分析，我们提出了通过表面极化产生手性的概念，这指的是手性旋向通过降低表面能量选择特定取向的轴矩的现象。 我们进一步建立了逆过程，称为通过表面极化产生手性，其中轴性反过来决定优选的手性。 这些相互耦合为稳定手性和轴性的单畴状态开辟了新途径。 它们还暗示了界面功能，包括手性和轴性分子的选择性吸附。
In condensed matter physics, a broad spectrum of physical characteristics, such as chirality, axiality, and polarity, arises as a direct consequence of the underlying symmetry of the system. We here theoretically investigate the effective coupling between chirality and axiality at their domain boundaries, mediated by polarity. Based on symmetry considerations and model analyses, we propose the concept of chirality-induced axiality via surface polarization, which refers to a phenomenon where the handedness of chirality selects an axial moment with a particular orientation by lowering its energy at the surface. We further establish the inverse process, termed axiality-induced chirality via surface polarization, whereby axiality in turn dictates the preferred chirality. These reciprocal couplings open a new pathway for stabilizing single-domain states of chirality and axiality. They further imply interfacial functionalities, including the selective adsorption of chiral and axial molecules.
- [17] arXiv:2510.18574 (交叉列表自 hep-th) [中文pdf, pdf, html, 其他]
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标题： 三维质量分数的协变场论标题： Covariant field theory of 3D massive fractons评论： 33页，无图表，即将发表于《欧洲物理杂志C》（EPJ C）主题： 高能物理 - 理论 (hep-th) ; 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 强关联电子 (cond-mat.str-el) ; 广义相对论与量子宇宙学 (gr-qc)
我们构建了一个协变且规范不变的理论，用于描述三维时空中的质量分形子，该理论基于一个对称的二阶张量场。 该模型包含一个类似Chern-Simons的项，其起到双重作用：它为张量规范场生成拓扑质量，同时作为内在分形物质的来源。 这种双重机制是新颖的，并导致由质量化的Klein-Gordon方程描述的传播分形自由度。 该理论传播两个自由度——一个有质量，一个无质量——在无质量极限下它们的数量保持不变，类似于Deser-Jackiw-Templeton的Maxwell-Chern-Simons机制。 我们分析了所得的运动方程，并表明内在分形物质满足高斯定律和安培类似定律，具有守恒的偶极矩和四极矩的迹。 在与外部物质耦合时，会出现第二个分形子领域，导致内在和外在子系统共存，具有不同的移动性和守恒性质。 我们的模型提供了一个统一的框架，用于描述具有内部结构的质量分形子，并为其相互作用和扩展提供了协变设置。
We construct a covariant and gauge-invariant theory describing massive fractons in three spacetime dimensions, based on a symmetric rank-2 tensor field. The model includes a Chern-Simons-like term that plays a dual role: it generates a topological mass for the tensor gauge field and simultaneously acts as a source of intrinsic fractonic matter. This dual mechanism is novel and leads to a propagating fractonic degree of freedom described by a massive Klein-Gordon equation. The theory propagates two degrees of freedom -- one massive, one massless -- whose number is preserved in the massless limit, in analogy with the Maxwell-Chern-Simons mechanism of Deser-Jackiw-Templeton. We analyze the resulting equations of motion and show that the intrinsic fractonic matter satisfies Gauss- and Amp\`ere-like laws, with conserved dipole and trace of the quadrupole moment. Upon coupling to external matter, a second fractonic sector emerges, leading to a coexistence of intrinsic and extrinsic subsystems with different mobility and conservation properties. Our model provides a unified framework for describing massive fractons with internal structure, and offers a covariant setting for exploring their interactions and extensions.
交叉提交 (展示 3 之 3 条目 )
- [18] arXiv:2505.05044 (替换) [中文pdf, pdf, html, 其他]
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标题： 基于量子流体动力学形式的超缩放5纳米硅纳米线场效应晶体管中声子拖曳的空间映射标题： Spatially Mapping Phonon Drag in Ultrascaled 5-nm Silicon Nanowire Field-Effect Transistor Based on a Quantum Hydrodynamic Formalism期刊参考： J. 应用物理 138，135102 (2025)主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall)
随着对纳米电子器件更好性能和更低热能耗的需求不断增长，这成为半导体行业追求未来一代纳米晶体管的主要驱动力。 在过去15年中，根据摩尔定律预测的基于硅的纳米电子学微型化，推动了晶体管结构的大幅缩小，包括材料、设计和几何形状。 在这方面，电子器件界已将重点扩展到针对7纳米技术节点及更小的超缩放晶体管。 然而，这些新兴纳米器件也带来了热挑战，由于强电子-声子耦合，可能限制载流子传输。 在本研究中，我们研究了超缩放5纳米硅纳米线场效应晶体管中自加热效应的物理起源。 基于量子流体动力学方法，我们还提供了对声子拖曳效应对热导率贡献的解释。 我们报告了声子拖曳效应对5纳米全栅周围硅纳米线场效应晶体管电学和热学性能的影响。 我们的发现为由于相互电子-声子耦合导致的自加热起源提供了新的见解。 此外，我们证明在高偏压条件下，声子拖曳效应使热导率显著降低了近50%。
The growing demand for better performance and lower thermal energy dissipation in nanoelectronic devices is the major driving force of the semiconductor industry's quest for future generations of nanotransistors. Over the past 15 years, the miniaturization of silicon-based nanoelectronics predicted by Moore's law has driven an aggressive scaling down of transistor structures, including materials, design, and geometries. In this regard, the electronic device community has expanded its focus to ultrascaled transistors targeting the 7 nm technology node and beyond. However, these emerging nanodevices also present thermal challenges that can limit carrier transport as a result of strong electron-phonon coupling. In this work, we investigate the physical origin of self-heating effects in an ultrascaled 5 nm silicon nanowire field-effect transistor. Based on a quantum hydrodynamic approach, we also provide an explanation of the phonon drag contribution to thermal conductivity. We report the impact of the phonon drag effect on the electrical and thermal performance of 5 nm gate-all-around silicon nanowire field-effect transistors. Our findings provide new insight into the origin of self-heating as a result of mutual electron-phonon coupling. Furthermore, we demonstrate that the phonon drag effect significantly reduces thermal conductivity by nearly 50% under high-bias conditions.
- [19] arXiv:2505.13200 (替换) [中文pdf, pdf, html, 其他]
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标题： 强耦合下介观导体中的量子动力学不确定性关系标题： Quantum Kinetic Uncertainty Relations in Mesoscopic Conductors at Strong Coupling主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 统计力学 (cond-mat.stat-mech) ; 量子物理 (quant-ph)
运动不确定性关系（KURs）通过将信噪比（SNR）与系统的动态活动相联系，确立了量子输运的精度极限，在弱耦合区域有效，此时粒子输运占主导地位。 在强耦合下，量子相干性挑战了KURs的有效性，并质疑了活动性的概念本身。 在本通讯中，我们实现了两个不同但互补的主要结果。 首先，我们引入了一个适用于任意耦合的动态活动的一般定义，这揭示了在强耦合下标准KURs的失效。 其次，我们证明了一个适用于任意耦合强度的新不确定性关系，我们将其称为量子KUR（QKUR）。 这个QKUR对应于KUR的一个非平凡的量子扩展，涉及广义动态活动的基本贡献。 这两个成就提供了一个用于非平衡量子输运精度分析的通用框架，与从TURs到QTURs的转变[Phys. Rev. Lett. 135, 046302]密切相关。 在格林函数和兰道尔-布蒂克形式主义中得到了明确的稳态表达式。 我们以典型的量子相干介观器件为例来说明这些概念：一个由量子点接触夹紧的单量子通道以及开放的单量子点和双量子点系统。
Kinetic Uncertainty Relations (KURs) establish quantum transport precision limits by linking signal-to-noise ratio (SNR) to the system's dynamical activity, valid in the weak-coupling regime where particle-like transport dominates. At strong coupling, quantum coherence challenges the validity of KURs and questions the concept of activity itself. In this Letter, we achieve two distinct, yet complementary main results. First, we introduce a general definition of dynamical activity valid at arbitrary coupling, which reveals the breakdown of standard KURs at strong coupling. Second, we prove a novel uncertainty relation valid at arbitrary coupling strength, which we denote Quantum KUR (QKUR). This QKUR corresponds to a nontrivial quantum extension of KUR, involving fundamental contributions of the generalized dynamical activity. These two achievements provide a general framework for out-of-equilibrium quantum transport precision analysis, in close analogy with the transition from TURs to QTURs [Phys. Rev. Lett. 135, 046302]. Explicit steady-state expressions are obtained within Green's-function and Landauer-B\"uttiker formalisms. We illustrate these concepts for paradigmatic quantum-coherent mesoscopic devices: a single quantum channel pinched by a quantum point contact and open single- and double-quantum dot systems.
- [20] arXiv:2507.10763 (替换) [中文pdf, pdf, html, 其他]
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标题： 超流$^{3}$氦在磁场中的维度交叉标题： Dimensional crossover of superfluid $^{3}$He in a magnetic field评论： 37页主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 量子气体 (cond-mat.quant-gas) ; 强关联电子 (cond-mat.str-el) ; 超导性 (cond-mat.supr-con)
受在纳米尺度受限几何结构中对超流体$^3$氦的最近实验的启发，我们从理论上研究了在板状几何结构和垂直磁场下，随着受限尺寸变化时相关的相图。 我们的分析基于对三种不同边界条件下的$3\times 3$矩阵超流序参数的吉兹堡-朗道自由能进行最小化。 我们观察到，对于几百度纳米的板状高度和几特斯拉的磁场，3D系统的相图平滑地过渡到准二维极限。 我们指出，尽管底层方程看起来复杂，但可以对自由能泛函系数的一般值关于相结构做出许多精确的数值甚至解析陈述，这些陈述反过来可用于约束或测量这些参数。 为了指导未来的实验研究，我们计算了相图与压力、温度、板状高度和磁场的关系。
Motivated by recent experiments on superfluid $^3$He in nanoscale-confined geometries, we theoretically investigate the associated phase diagram in a slab geometry and perpendicular magnetic field as the size of confinement is varied. Our analysis is based on minimizing the Ginzburg--Landau free energy for the $3\times 3$ matrix superfluid order parameter for three different boundary conditions. We observe a smooth crossover from the phase diagram of the 3D system to the quasi-2D limit for slab heights of several hundred nanometres and magnetic fields of several kilogauss. We illuminate that, despite the apparent complexity of the underlying equations, many precise numerical and even analytical statements can be made about the phase structure for general values of the coefficients of the free energy functional, which can in turn be used to constrain or measure these parameters. To guide future experimental studies, we compute the phase diagram in dependence of pressure, temperature, slab height, and magnetic field.
- [21] arXiv:2509.15708 (替换) [中文pdf, pdf, html, 其他]
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标题： 太赫兹辐射诱导的过渡金属二硫属化物单层中的吸引-排斥费米极化子转换标题： Terahertz radiation induced attractive-repulsive Fermi polaron conversion in transition metal dichalcogenide monolayers评论： 13页，5图主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 材料科学 (cond-mat.mtrl-sci) ; 其他凝聚态物理 (cond-mat.other)
我们对单层过渡金属二硫化物中由太赫兹辐射引起的吸引和排斥费米极化子态之间的跃迁进行了理论研究。 超越简单的少粒子三离子图像，我们发展了一个多体描述，明确考虑了与驻留电荷载流子费米海的相关性。 我们计算了直接光学转换过程的速率，该过程有一个阈值，即太赫兹光子能量等于费米极化子结合能。 由于最终态电子-激子散射与费米海空穴的三离子相关性，该过程在阈值附近具有特征频率依赖性。 此外，我们证明强烈的太赫兹脉冲可以通过德鲁德吸收显著加热电子气，从而通过热电子与极化子之间的碰撞产生额外的间接转换机制，该机制表现出对电子温度的强指数依赖性。 我们的结果揭示了多体相关性和热效应在二维半导体中激子复合体太赫兹驱动动力学中的重要作用。
We present a theoretical study of terahertz radiation-induced transitions between attractive and repulsive Fermi polaron states in monolayers of transition metal dichalcogenides. Going beyond the simple few-particle trion picture, we develop a many-body description that explicitly accounts for correlations with the Fermi sea of resident charge carriers. We calculate the rate of the direct optical conversion process which has a threshold where the terahertz photon energy equals to the Fermi polaron binding energy. This process features a characteristic frequency dependence near the threshold, due to final-state electron-exciton scattering related to the trion correlation with the Fermi sea hole. Furthermore, we demonstrate that intense terahertz pulses can significantly heat the electron gas via Drude absorption enabling an additional, indirect conversion mechanism through collisions between hot electrons and polarons, which exhibits a strong exponential dependence on the electron temperature. Our results reveal the important role of many-body correlations and thermal effects in the terahertz-driven dynamics of excitonic complexes in two-dimensional semiconductors.
- [22] arXiv:2510.17683 (替换) [中文pdf, pdf, html, 其他]
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标题： 通过半导体-超导光子场效应热晶体管实现巨大的热调制标题： Giant thermal modulation via a semiconductor-superconductor photonic field-effect heat transistorSebastiano Battisti, Matteo Pioldi, Alessandro Paghi, Giorgio De Simoni, Alessandro Braggio, Giulio Senesi, Lucia Sorba, Francesco Giazotto评论： 24页，8图主题： 中尺度与纳米尺度物理 (cond-mat.mes-hall) ; 超导性 (cond-mat.supr-con)
我们展示了一种在场效应可控制的半导体-超导体混合结构中热调制的突破性演示，其中加热机制仅是辐射性的。 该结构由两个通过$\sim 1$ mm 分离的库，并通过一个完全非 galvanic 的电路相互连接，从而实现从热库到冷库的黑体辐射传输。 我们的器件利用超导 Josephson 场效应晶体管，在电路中实现无磁场的栅极可调热流调控。 虽然先前的研究表明静电调制热传输特性的潜力，但我们的框架展示了高达$\sim 45$ mK 的温度调制，比先前发现超过一个数量级。 此外，它在浴温为$30$ mK 时证明了热转移阻抗为$\sim 20$ mK/V。 此类系统的发展在推进量子芯片和辐射传感器中的热量管理和路由方面具有巨大的前景，因为它能够在热源远离且非 galvanically 耦合的情况下，对指定结构的热流实现精确的非本地控制。
We present a groundbreaking demonstration of thermal modulation in a field-effect-controllable semiconductor-superconductor hybrid structure, wherein the heating mechanism is exclusively radiative. The architecture comprises two reservoirs separated by $\sim 1$ mm and interconnected via a completely non-galvanic electrical circuit, enabling the transfer of black-body radiation from the hot to the cold reservoir. Our device utilizes a superconducting Josephson field-effect transistor to achieve magnetic-field-free gate-tunable regulation of heat currents within the circuit. While prior studies have indicated the potential for electrostatic modulation of thermal transport properties, our framework demonstrates a temperature modulation of up to $\sim 45$ mK, exceeding prior findings by more than an order of magnitude. Furthermore, it proves a thermal transimpedance of $\sim 20$ mK/V at a bath temperature of $30$ mK. The development of such systems holds substantial promise for advancing heat management and routing in quantum chips and radiation sensors, as it enables precise nonlocal control of heat flow towards a designated structure, even when the heat source is distant and non-galvanically coupled.
- [23] arXiv:2507.23022 (替换) [中文pdf, pdf, html, 其他]
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标题： p波非厄米约瑟夫森结中的异常安德烈夫谱和超电流标题： Exceptional Andreev spectrum and supercurrent in p-wave non-Hermitian Josephson junctions评论： 8页，4图；修订版，增加了关于异常点和马约拉纳零模的讨论主题： 超导性 (cond-mat.supr-con) ; 中尺度与纳米尺度物理 (cond-mat.mes-hall)
我们研究了一维$p$-波非厄米约瑟夫森结（NHJJ）中的安德烈夫束缚态谱和超电流。所研究的 NHJJ 由两个拓扑$p$-波超导体通过一个非厄米耗散结连接而成。从有效的非厄米 Bogoliubov-de Gennes 体哈密顿量出发，我们发现安德烈夫准束缚态的复数谱中出现了一对异常点。这两个零能的异常点相对于约瑟夫森相位差$\phi=\pi$对称分布，在此位置存在马约拉纳零模。值得注意的是，这些异常点来源于引入非厄米性后的马约拉纳零模对，并且具有拓扑保护性。通过分析结处的非厄米散射过程，我们明确展示了准粒子通过散射振幅概率衰减而损失的情况。此外，我们直接通过非弹性安德烈夫反射振幅获得了超电流，这为 NHJJs 中输运性质提供了更直观的解释。超电流作为$\phi$的函数在异常点之间连续变化。未观察到临界电流的增强。我们还将分析推广到混合$s$-$p$波 NHJJ 的情况。我们的结果为存在马约拉纳零模、异常点和非厄米性的约瑟夫森结的输运特性提供了新的见解。
We investigate the spectrum of Andreev bound states and supercurrent in a $p$-wave non-Hermitian Josephson junction (NHJJ) in one dimension. The studied NHJJ is composed of two topological $p$-wave superconductors connected by a non-Hermitian dissipative junction. Starting from the effective non-Hermitian Bogoliubov-de Gennes bulk Hamiltonian, we find that a pair of exceptional points emerge in the complex spectrum of Andreev quasi-bound states. The two exceptional points with zero energy locate symmetrically with respect to Josephson phase difference $\phi=\pi$, at which a Majorana zero mode persists. Notably, the exceptional points descend from a pair of Majorana zero modes after turning on the non-Hermiticity and are topologically protected. By analyzing the non-Hermitian scattering process at the junction, we explicitly demonstrate the loss of quasiparticles through the decay of scattering amplitude probabilities. Furthermore, we obtain the supercurrent directly by the inelastic Andreev reflection amplitudes, which provides a more intuitive interpretation of transport properties in NHJJs. The supercurrent varies continuously as a function of $\phi$ across the exceptional points. No enhancement of critical current is observed. We also generalize our analysis to a mixed $s$-$p$ wave NHJJ. Our results provide new insights on transport properties of Josephson junctions in presence of Majorana zero modes, exceptional points, and non-Hermiticity.