Pub Date : 2025-03-11DOI: 10.1103/physrevlett.134.103201
Sajad Azizi, Ulf Saalmann, Jan M. Rost
We predict a near-threshold (“zero energy”) peak in multiphoton ionization for a dynamical regime where the photon frequency is large compared to the binding energy of the electron. The peak position does not depend on the laser frequency but on the binding energy and the pulse duration. The effect originates from the fact that bound-continuum dipole transitions are stronger than continuum-continuum ones. To clearly observe this zero-energy photoelectric effect, the spectral width of the laser pulse should be comparable to the binding energy of the ionized orbital, and the second ionization potential should be larger than the photon energy. This suggests negative ions as ideal candidates for corresponding experiments. Published by the American Physical Society2025
{"title":"Zero-Energy Photoelectric Effect","authors":"Sajad Azizi, Ulf Saalmann, Jan M. Rost","doi":"10.1103/physrevlett.134.103201","DOIUrl":"https://doi.org/10.1103/physrevlett.134.103201","url":null,"abstract":"We predict a near-threshold (“zero energy”) peak in multiphoton ionization for a dynamical regime where the photon frequency is large compared to the binding energy of the electron. The peak position does not depend on the laser frequency but on the binding energy and the pulse duration. The effect originates from the fact that bound-continuum dipole transitions are stronger than continuum-continuum ones. To clearly observe this zero-energy photoelectric effect, the spectral width of the laser pulse should be comparable to the binding energy of the ionized orbital, and the second ionization potential should be larger than the photon energy. This suggests negative ions as ideal candidates for corresponding experiments. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"38 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143598982","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}
Pub Date : 2025-03-11DOI: 10.1103/physrevlett.134.104003
Vatsal Sanjay, Detlef Lohse
The dynamics of drop impact on a rigid surface strongly depends on the droplet’s velocity, its size, and its material properties. The main characteristics are the droplet’s force exerted on the surface and its maximal spreading radius. The crucial question is how do they depend on the (dimensionless) control parameters, which are the Weber number We (nondimensionalized kinetic energy) and the Ohnesorge number Oh (dimensionless viscosity). Here, we perform direct numerical simulations over the huge parameter range 1≤We≤103 and 10−3≤Oh≤102 and in particular develop a unifying theoretical approach, which is inspired by the Grossmann-Lohse theory for wall-bounded turbulence [Grossmann and Lohse, ; ]. The key idea is to split the energy dissipation rate into the different phases of the impact process, in which different physical mechanisms dominate. The theory can consistently and quantitatively account for the We and Oh dependences of the maximal impact force and the maximal spreading diameter over the huge parameter space. It also clarifies why viscous dissipation plays a significant role during impact, even for low-viscosity droplets (low Oh), in contrast to what had been assumed in some prior theories. Published by the American Physical Society2025
液滴撞击刚性表面的动态很大程度上取决于液滴的速度、大小及其材料特性。主要特征是液滴对表面施加的力及其最大扩散半径。关键问题是它们如何取决于（无量纲）控制参数，即韦伯数 We（无量纲化动能）和奥内索尔格数 Oh（无量纲化粘度）。在这里，我们在 1≤We≤103 和 10-3≤Oh≤102 的巨大参数范围内进行了直接数值模拟，特别是开发了一种统一的理论方法，该方法受到了壁界湍流的格罗斯曼-洛塞理论的启发[Grossmann and Lohse, ; ]。其主要思想是将能量耗散率分为撞击过程的不同阶段，在这些阶段中，不同的物理机制占主导地位。在巨大的参数空间内，该理论可以一致地定量解释最大冲击力和最大扩展直径的 We 和 Oh 相关性。该理论还阐明了为什么粘滞耗散在撞击过程中起着重要作用，即使对于低粘度液滴（低 Oh）也是如此，这与之前一些理论的假设截然不同。 美国物理学会出版 2025
{"title":"Unifying Theory of Scaling in Drop Impact: Forces and Maximum Spreading Diameter","authors":"Vatsal Sanjay, Detlef Lohse","doi":"10.1103/physrevlett.134.104003","DOIUrl":"https://doi.org/10.1103/physrevlett.134.104003","url":null,"abstract":"The dynamics of drop impact on a rigid surface strongly depends on the droplet’s velocity, its size, and its material properties. The main characteristics are the droplet’s force exerted on the surface and its maximal spreading radius. The crucial question is how do they depend on the (dimensionless) control parameters, which are the Weber number W</a:mi>e</a:mi></a:mrow></a:math> (nondimensionalized kinetic energy) and the Ohnesorge number <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:mrow><c:mi>O</c:mi><c:mi>h</c:mi></c:mrow></c:math> (dimensionless viscosity). Here, we perform direct numerical simulations over the huge parameter range <e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><e:mrow><e:mn>1</e:mn><e:mo>≤</e:mo><e:mi>W</e:mi><e:mi>e</e:mi><e:mo>≤</e:mo><e:msup><e:mrow><e:mn>10</e:mn></e:mrow><e:mrow><e:mn>3</e:mn></e:mrow></e:msup></e:mrow></e:math> and <g:math xmlns:g=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><g:mrow><g:msup><g:mrow><g:mn>10</g:mn></g:mrow><g:mrow><g:mo>−</g:mo><g:mn>3</g:mn></g:mrow></g:msup><g:mo>≤</g:mo><g:mi>O</g:mi><g:mi>h</g:mi><g:mo>≤</g:mo><g:msup><g:mrow><g:mn>10</g:mn></g:mrow><g:mrow><g:mn>2</g:mn></g:mrow></g:msup></g:mrow></g:math> and in particular develop a unifying theoretical approach, which is inspired by the Grossmann-Lohse theory for wall-bounded turbulence [Grossmann and Lohse, ; ]. The key idea is to split the energy dissipation rate into the different phases of the impact process, in which different physical mechanisms dominate. The theory can consistently and quantitatively account for the <i:math xmlns:i=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><i:mrow><i:mi>W</i:mi><i:mi>e</i:mi></i:mrow></i:math> and <k:math xmlns:k=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><k:mrow><k:mi>O</k:mi><k:mi>h</k:mi></k:mrow></k:math> dependences of the maximal impact force and the maximal spreading diameter over the huge parameter space. It also clarifies why viscous dissipation plays a significant role during impact, even for low-viscosity droplets (low <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><m:mi>O</m:mi><m:mi>h</m:mi></m:math>), in contrast to what had been assumed in some prior theories. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"17 2 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143598984","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}
Pub Date : 2025-03-11DOI: 10.1103/physrevlett.134.107301
Stefanie M. Kampa, Florian Sammüller, Matthias Schmidt, Robert Evans
The excess free energy functional of classical density functional theory depends upon the type of fluid model, specifically on the choice of (pair) potential. This functional is unknown in general and is approximated reliably only in special cases. We present a machine learning scheme for training a neural network that acts as a generic metadensity functional for truncated but otherwise arbitrary pair potentials. Automatic differentiation and neural functional calculus then yield, for one-dimensional fluids, accurate predictions for inhomogeneous states and immediate access to the pair distribution function. The approach provides a means of addressing a fundamental problem in the physics of liquids and for soft matter design: “How do we best invert structural data to obtain the pair potential?” Published by the American Physical Society2025
{"title":"Metadensity Functional Theory for Classical Fluids: Extracting the Pair Potential","authors":"Stefanie M. Kampa, Florian Sammüller, Matthias Schmidt, Robert Evans","doi":"10.1103/physrevlett.134.107301","DOIUrl":"https://doi.org/10.1103/physrevlett.134.107301","url":null,"abstract":"The excess free energy functional of classical density functional theory depends upon the type of fluid model, specifically on the choice of (pair) potential. This functional is unknown in general and is approximated reliably only in special cases. We present a machine learning scheme for training a neural network that acts as a generic metadensity functional for truncated but otherwise arbitrary pair potentials. Automatic differentiation and neural functional calculus then yield, for one-dimensional fluids, accurate predictions for inhomogeneous states and immediate access to the pair distribution function. The approach provides a means of addressing a fundamental problem in the physics of liquids and for soft matter design: “How do we best invert structural data to obtain the pair potential?” <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"39 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143598986","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}
Pub Date : 2025-03-10DOI: 10.1103/physrevlett.134.106501
Andreas Gleis, Seung-Sup B. Lee, Gabriel Kotliar, Jan von Delft
We study dynamical scaling associated with a Kondo-breakdown quantum-critical point (KB QCP) of the periodic Anderson model, treated by two-site cellular dynamical mean-field theory (2CDMFT). In the quantum-critical region, the dynamical staggered-spin susceptibility exhibits ω/T scaling. We propose a scaling ansatz that describes this behavior and reveals Planckian dissipation for the longest-lived excitations. The current susceptibility follows the same scaling, leading to strange-metal behavior for the optical conductivity and resistivity. Importantly, this behavior is driven by strong short-ranged vertex contributions, not single-particle decay. This suggests that the KB QCP described by 2CDMFT is a novel (i.e., disorder-free) strange-metal fixed point. Our results for the optical conductivity match experimental observations on YbRh2Si2 and CeCoIn5. Published by the American Physical Society2025
{"title":"Dynamical Scaling and Planckian Dissipation Due to Heavy-Fermion Quantum Criticality","authors":"Andreas Gleis, Seung-Sup B. Lee, Gabriel Kotliar, Jan von Delft","doi":"10.1103/physrevlett.134.106501","DOIUrl":"https://doi.org/10.1103/physrevlett.134.106501","url":null,"abstract":"We study dynamical scaling associated with a Kondo-breakdown quantum-critical point (KB QCP) of the periodic Anderson model, treated by two-site cellular dynamical mean-field theory (2CDMFT). In the quantum-critical region, the dynamical staggered-spin susceptibility exhibits ω</a:mi>/</a:mo>T</a:mi></a:mrow></a:math> scaling. We propose a scaling ansatz that describes this behavior and reveals Planckian dissipation for the longest-lived excitations. The current susceptibility follows the same scaling, leading to strange-metal behavior for the optical conductivity and resistivity. Importantly, this behavior is driven by strong short-ranged vertex contributions, not single-particle decay. This suggests that the KB QCP described by 2CDMFT is a novel (i.e., disorder-free) strange-metal fixed point. Our results for the optical conductivity match experimental observations on <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:mrow><c:msub><c:mrow><c:mi>YbRh</c:mi></c:mrow><c:mrow><c:mn>2</c:mn></c:mrow></c:msub><c:msub><c:mrow><c:mi>Si</c:mi></c:mrow><c:mrow><c:mn>2</c:mn></c:mrow></c:msub></c:mrow></c:math> and <e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><e:mrow><e:msub><e:mrow><e:mi>CeCoIn</e:mi></e:mrow><e:mrow><e:mn>5</e:mn></e:mrow></e:msub></e:mrow></e:math>. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"30 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143590199","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}
Pub Date : 2025-03-10DOI: 10.1103/physrevlett.134.101001
Pedro De la Torre Luque, Shyam Balaji, Joseph Silk
We demonstrate that the anomalous ionization rate observed in the Central Molecular Zone can be attributed to MeV dark matter annihilations into e+e− pairs for galactic dark matter profiles with slopes γ>1. The low annihilation cross sections required avoid cosmological constraints and imply no detectable inverse Compton, bremsstrahlung, or synchrotron emission in radio, x- and γ rays. The possible connection with the source of the unexplained 511 keV line emission in the Galactic Center suggests that both observations could be correlated and have a common origin. Published by the American Physical Society2025
{"title":"Anomalous Ionization in the Central Molecular Zone by Sub-GeV Dark Matter","authors":"Pedro De la Torre Luque, Shyam Balaji, Joseph Silk","doi":"10.1103/physrevlett.134.101001","DOIUrl":"https://doi.org/10.1103/physrevlett.134.101001","url":null,"abstract":"We demonstrate that the anomalous ionization rate observed in the Central Molecular Zone can be attributed to MeV dark matter annihilations into e</a:mi>+</a:mo></a:msup>e</a:mi>−</a:mo></a:msup></a:math> pairs for galactic dark matter profiles with slopes <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:mi>γ</c:mi><c:mo>></c:mo><c:mn>1</c:mn></c:math>. The low annihilation cross sections required avoid cosmological constraints and imply no detectable inverse Compton, bremsstrahlung, or synchrotron emission in radio, x- and <e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><e:mi>γ</e:mi></e:math> rays. The possible connection with the source of the unexplained 511 keV line emission in the Galactic Center suggests that both observations could be correlated and have a common origin. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"2 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143590169","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}
Pub Date : 2025-03-07DOI: 10.1103/physrevlett.134.096302
Florian Kluibenschedl, Georgios M. Koutentakis, Ragheed Alhyder, Mikhail Lemeshko
We demonstrate the formation of ferroelectric domain-wall polarons in a minimal two-dimensional lattice model of electrons interacting with rotating dipoles. Along the domain wall, the rotors polarize in opposite directions, causing the electron to localize along a particular lattice direction. The rotor-electron coupling is identified as the origin of a structural instability in the crystal that leads to the domain-wall formation via a symmetry-breaking process. Our results provide the first theoretical description of ferroelectric polarons, as discussed in the context of soft semiconductors. Published by the American Physical Society2025
{"title":"Domain-Wall Ferroelectric Polarons in a Two-Dimensional Rotor Lattice Model","authors":"Florian Kluibenschedl, Georgios M. Koutentakis, Ragheed Alhyder, Mikhail Lemeshko","doi":"10.1103/physrevlett.134.096302","DOIUrl":"https://doi.org/10.1103/physrevlett.134.096302","url":null,"abstract":"We demonstrate the formation of ferroelectric domain-wall polarons in a minimal two-dimensional lattice model of electrons interacting with rotating dipoles. Along the domain wall, the rotors polarize in opposite directions, causing the electron to localize along a particular lattice direction. The rotor-electron coupling is identified as the origin of a structural instability in the crystal that leads to the domain-wall formation via a symmetry-breaking process. Our results provide the first theoretical description of ferroelectric polarons, as discussed in the context of soft semiconductors. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"9 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143575360","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}
Quantum turbulence is a far-from-equilibrium process characterized by high nonlinearity. Holographic duality provides a systematic framework for simulating the decaying (3+1)-dimensional quantum turbulence by numerically solving the dual Abelian-Higgs theory in a (4+1)-dimensional black hole background. We reveal that different types of decay behavior of the total vortex line density L emerge depending on the initial vortex line density, ranging from L∼t−1.5 to L∼t−1, similar to the experimental observation of He3 in Bradley [], and of He4 in Stalp [] and in Walmsley and Golov []. Furthermore, by measuring the energy flux at the black hole horizon, we determine that the energy dissipation rate dE/dt is proportional to the square of the total vortex line density, consistent with the vortex line decay equation proposed by W. F. Vinen and also the experimental measurement in . Published by the American Physical Society2025
{"title":"Dissipation and Decay of Three-Dimensional Holographic Quantum Turbulence","authors":"Hua-Bi Zeng, Chuan-Yin Xia, Wei-Can Yang, Yu Tian, Makoto Tsubota","doi":"10.1103/physrevlett.134.091603","DOIUrl":"https://doi.org/10.1103/physrevlett.134.091603","url":null,"abstract":"Quantum turbulence is a far-from-equilibrium process characterized by high nonlinearity. Holographic duality provides a systematic framework for simulating the decaying (3</a:mn>+</a:mo>1</a:mn></a:mrow></a:math>)-dimensional quantum turbulence by numerically solving the dual Abelian-Higgs theory in a (<c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:mrow><c:mn>4</c:mn><c:mo>+</c:mo><c:mn>1</c:mn></c:mrow></c:math>)-dimensional black hole background. We reveal that different types of decay behavior of the total vortex line density <e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><e:mi>L</e:mi></e:math> emerge depending on the initial vortex line density, ranging from <g:math xmlns:g=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><g:mi>L</g:mi><g:mo>∼</g:mo><g:msup><g:mi>t</g:mi><g:mrow><g:mo>−</g:mo><g:mn>1.5</g:mn></g:mrow></g:msup></g:math> to <i:math xmlns:i=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><i:mrow><i:mi>L</i:mi><i:mo>∼</i:mo><i:msup><i:mrow><i:mi>t</i:mi></i:mrow><i:mrow><i:mo>−</i:mo><i:mn>1</i:mn></i:mrow></i:msup></i:mrow></i:math>, similar to the experimental observation of <k:math xmlns:k=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><k:mrow><k:mmultiscripts><k:mrow><k:mi>He</k:mi></k:mrow><k:mprescripts/><k:none/><k:mn>3</k:mn></k:mmultiscripts></k:mrow></k:math> in Bradley [], and of <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><m:mrow><m:mmultiscripts><m:mrow><m:mi>He</m:mi></m:mrow><m:mprescripts/><m:none/><m:mn>4</m:mn></m:mmultiscripts></m:mrow></m:math> in Stalp [] and in Walmsley and Golov []. Furthermore, by measuring the energy flux at the black hole horizon, we determine that the energy dissipation rate <o:math xmlns:o=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><o:mi>d</o:mi><o:mi>E</o:mi><o:mo>/</o:mo><o:mi>d</o:mi><o:mi>t</o:mi></o:math> is proportional to the square of the total vortex line density, consistent with the vortex line decay equation proposed by W. F. Vinen and also the experimental measurement in . <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"13 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143575192","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}
Pub Date : 2025-03-07DOI: 10.1103/physrevlett.134.093202
Stefanos Carlström, Rezvan Tahouri, Asimina Papoulia, Jan Marcus Dahlström, Misha Yu Ivanov, Olga Smirnova, Serguei Patchkovskii
It has been shown by Fano [1] that photoionization of a cesium atom by a laser pulse tuned to the vicinity of a Cooper minimum generates spin-polarized electrons. Here we show that while photoionization of rare gases does not provide large spin polarization in the vicinity of the Cooper minimum, the Fano resonances yield much higher overall spin polarization (≥40%). The spin polarization increases in angle-resolved photoelectron spectra, and reaches 100% when measured in coincidence with the photoion. A common feature of both Cooper minima and Fano resonances, is the large variation of the photoinization cross section over photon energy, which proves to be vital for efficient generation of spin-polarized electrons. We provide a general framework for achieving spin polarization in photoionization irrespective of the ionization regime. Published by the American Physical Society2025
{"title":"Spin-Polarized Photoelectrons in the Vicinity of Spectral Features","authors":"Stefanos Carlström, Rezvan Tahouri, Asimina Papoulia, Jan Marcus Dahlström, Misha Yu Ivanov, Olga Smirnova, Serguei Patchkovskii","doi":"10.1103/physrevlett.134.093202","DOIUrl":"https://doi.org/10.1103/physrevlett.134.093202","url":null,"abstract":"It has been shown by Fano [1] that photoionization of a cesium atom by a laser pulse tuned to the vicinity of a Cooper minimum generates spin-polarized electrons. Here we show that while photoionization of rare gases does not provide large spin polarization in the vicinity of the Cooper minimum, the Fano resonances yield much higher overall spin polarization (</a:mo>≥</a:mo>40</a:mn>%</a:mo>)</a:mo></a:mrow></a:math>. The spin polarization increases in angle-resolved photoelectron spectra, and reaches 100% when measured in coincidence with the photoion. A common feature of both Cooper minima and Fano resonances, is the large variation of the photoinization cross section over photon energy, which proves to be vital for efficient generation of spin-polarized electrons. We provide a general framework for achieving spin polarization in photoionization irrespective of the ionization regime. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"13 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143575188","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}
Pub Date : 2025-03-07DOI: 10.1103/physrevlett.134.093002
Lamberto Oltra, Luis Méndez, Ismanuel Rabadán, Klaas Bijlsma, Emiel de Wit, Ronnie Hoekstra
Remarkably large double electron capture cross sections, on the scale of 10−15cm2, are observed in low-energy (<50eV/u) collisions between Sn3+ and H2. Given that the reaction is energetically highly unfavorable, one would expect negligibly small cross sections. Through the propagation of vibrational wave packets on coupled multiple potential energy surfaces, a novel charge transfer mechanism, driven in tandem by ion motion and molecular vibration, is revealed, offering insights into the unusual energy dependence of the measured cross sections. Published by the American Physical Society2025
{"title":"Sequential Synchronous Mechanism for Double-Electron Capture: Insights into Unforeseen Large Cross Sections in Low-Energy Sn3++H2 Collisions","authors":"Lamberto Oltra, Luis Méndez, Ismanuel Rabadán, Klaas Bijlsma, Emiel de Wit, Ronnie Hoekstra","doi":"10.1103/physrevlett.134.093002","DOIUrl":"https://doi.org/10.1103/physrevlett.134.093002","url":null,"abstract":"Remarkably large double electron capture cross sections, on the scale of 10</a:mn></a:mrow>−</a:mo>15</a:mn></a:mrow></a:msup></a:mtext></a:mtext>cm</a:mi></a:mrow>2</a:mn></a:mrow></a:msup></a:mrow></a:math>, are observed in low-energy (<c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:mrow><c:mo><</c:mo><c:mn>50</c:mn><c:mtext> </c:mtext><c:mtext> </c:mtext><c:mrow><c:mi>eV</c:mi><c:mo>/</c:mo><c:mi mathvariant=\"normal\">u</c:mi></c:mrow></c:mrow></c:math>) collisions between <f:math xmlns:f=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><f:msup><f:mi>Sn</f:mi><f:mrow><f:mn>3</f:mn><f:mo>+</f:mo></f:mrow></f:msup></f:math> and <h:math xmlns:h=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><h:msub><h:mi mathvariant=\"normal\">H</h:mi><h:mn>2</h:mn></h:msub></h:math>. Given that the reaction is energetically highly unfavorable, one would expect negligibly small cross sections. Through the propagation of vibrational wave packets on coupled multiple potential energy surfaces, a novel charge transfer mechanism, driven in tandem by ion motion and molecular vibration, is revealed, offering insights into the unusual energy dependence of the measured cross sections. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"59 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143575189","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}
Pub Date : 2025-03-07DOI: 10.1103/physrevlett.134.096002
J. Knapp, J. Nyéki, H. Patel, F. Ziouzia, B. P. Cowan, J. Saunders
We previously reported the discovery of a two-dimensional He4 supersolid; a state with intertwined density wave and superfluid order, observed in the second layer of He4 adsorbed on graphite. In this Letter we provide direct evidence for the density wave order, obtained by doping the layer with a small concentration of He3 atoms (impuritons). The heat capacity, magnetization and NMR relaxation times of the He3 were measured over a wide temperature range from 200μK to 500 mK. They provide evidence for changes in the ground state in the second layer film as the amount of He4 is increased at various fixed He3 doses. Clear evidence is obtained for a solid second layer film, matching the regime of superfluid response previously observed in pure He4 films. Published by the American Physical Society2025
{"title":"Thermodynamic Evidence for Density Wave Order in a Two Dimensional He4 Supersolid","authors":"J. Knapp, J. Nyéki, H. Patel, F. Ziouzia, B. P. Cowan, J. Saunders","doi":"10.1103/physrevlett.134.096002","DOIUrl":"https://doi.org/10.1103/physrevlett.134.096002","url":null,"abstract":"We previously reported the discovery of a two-dimensional He</a:mi></a:mrow>4</a:mn></a:mrow></a:mmultiscripts></a:mrow></a:math> supersolid; a state with intertwined density wave and superfluid order, observed in the second layer of <c:math xmlns:c=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><c:mrow><c:mmultiscripts><c:mrow><c:mi>He</c:mi></c:mrow><c:mprescripts/><c:none/><c:mrow><c:mn>4</c:mn></c:mrow></c:mmultiscripts></c:mrow></c:math> adsorbed on graphite. In this Letter we provide direct evidence for the density wave order, obtained by doping the layer with a small concentration of <e:math xmlns:e=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><e:mrow><e:mmultiscripts><e:mrow><e:mi>He</e:mi></e:mrow><e:mprescripts/><e:none/><e:mrow><e:mn>3</e:mn></e:mrow></e:mmultiscripts></e:mrow></e:math> atoms (impuritons). The heat capacity, magnetization and NMR relaxation times of the <g:math xmlns:g=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><g:mrow><g:mmultiscripts><g:mrow><g:mi>He</g:mi></g:mrow><g:mprescripts/><g:none/><g:mrow><g:mn>3</g:mn></g:mrow></g:mmultiscripts></g:mrow></g:math> were measured over a wide temperature range from <i:math xmlns:i=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><i:mrow><i:mn>200</i:mn><i:mtext> </i:mtext><i:mtext> </i:mtext><i:mi mathvariant=\"normal\">μ</i:mi><i:mi mathvariant=\"normal\">K</i:mi></i:mrow></i:math> to 500 mK. They provide evidence for changes in the ground state in the second layer film as the amount of <m:math xmlns:m=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><m:mrow><m:mmultiscripts><m:mrow><m:mi>He</m:mi></m:mrow><m:mprescripts/><m:none/><m:mrow><m:mn>4</m:mn></m:mrow></m:mmultiscripts></m:mrow></m:math> is increased at various fixed <o:math xmlns:o=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><o:mrow><o:mmultiscripts><o:mrow><o:mi>He</o:mi></o:mrow><o:mprescripts/><o:none/><o:mrow><o:mn>3</o:mn></o:mrow></o:mmultiscripts></o:mrow></o:math> doses. Clear evidence is obtained for a solid second layer film, matching the regime of superfluid response previously observed in pure <q:math xmlns:q=\"http://www.w3.org/1998/Math/MathML\" display=\"inline\"><q:mrow><q:mmultiscripts><q:mrow><q:mi>He</q:mi></q:mrow><q:mprescripts/><q:none/><q:mrow><q:mn>4</q:mn></q:mrow></q:mmultiscripts></q:mrow></q:math> films. <jats:supplementary-material> <jats:copyright-statement>Published by the American Physical Society</jats:copyright-statement> <jats:copyright-year>2025</jats:copyright-year> </jats:permissions> </jats:supplementary-material>","PeriodicalId":20069,"journal":{"name":"Physical review letters","volume":"52 1","pages":""},"PeriodicalIF":8.6,"publicationDate":"2025-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143575354","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}
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