Pub Date : 2024-08-31DOI: 10.1038/s42005-024-01774-8
LZ Collaboration
Weakly interacting massive particles (WIMPs) may interact with a virtual pion that is exchanged between nucleons. This interaction channel is important to consider in models where the spin-independent isoscalar channel is suppressed. Using data from the first science run of the LUX-ZEPLIN dark matter experiment, containing 60 live days of data in a 5.5 tonne fiducial mass of liquid xenon, we report the results on a search for WIMP-pion interactions. We observe no significant excess and set an upper limit of 1.5 × 10−46 cm2 at a 90% confidence level for a WIMP mass of 33 GeV/c2 for this interaction. Cosmological evidence suggests that nonluminous dark matter comprises 27% of the energy density of the universe, with weakly interacting massive particles (WIMPs) being a favoured candidate. Here, the authors perform a search for WIMP-like dark matter interacting with a virtual particle that is exchanges between xenon nucleons.
{"title":"Probing the scalar WIMP-pion coupling with the first LUX-ZEPLIN data","authors":"LZ Collaboration","doi":"10.1038/s42005-024-01774-8","DOIUrl":"10.1038/s42005-024-01774-8","url":null,"abstract":"Weakly interacting massive particles (WIMPs) may interact with a virtual pion that is exchanged between nucleons. This interaction channel is important to consider in models where the spin-independent isoscalar channel is suppressed. Using data from the first science run of the LUX-ZEPLIN dark matter experiment, containing 60 live days of data in a 5.5 tonne fiducial mass of liquid xenon, we report the results on a search for WIMP-pion interactions. We observe no significant excess and set an upper limit of 1.5 × 10−46 cm2 at a 90% confidence level for a WIMP mass of 33 GeV/c2 for this interaction. Cosmological evidence suggests that nonluminous dark matter comprises 27% of the energy density of the universe, with weakly interacting massive particles (WIMPs) being a favoured candidate. Here, the authors perform a search for WIMP-like dark matter interacting with a virtual particle that is exchanges between xenon nucleons.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":null,"pages":null},"PeriodicalIF":5.4,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01774-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142100555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-30DOI: 10.1038/s42005-024-01787-3
Jaideep Katuri, Navneet Kaur, William Uspal, Allison Cornelius, David Quashie Jr., Jamel Ali
Ensembles of suspended spinning particles in liquids form a distinct category of active matter systems known as chiral fluids. Recent experimental instances of dense chiral fluids have comprised of spinning colloidal magnets powered by an external rotating magnetic field. These particles interact through both magnetic and hydrodynamic forces, organizing collectively into circulating clusters characterized by unidirectional edge flows. Here, we externally drive the collective behavior of spinning colloids by leveraging diffusiophoretic interactions among the geometrically anisotropic particles. We show that these nanoscale interfacial flows lead to the formation of bound states between spinning colloids that are stabilized through near-field hydrodynamic and chemical interactions. At a collective level, we demonstrate that added diffusiophoretic interactions cause a loss in structural cohesion of the circulating clusters and promote expansion, while preserving global cluster inter-connectivity. The expanded cluster state is characterized by the formation of a dynamic interconnected network promoted by axi-asymmetric interactions around particles with attractive dipolar interactions dominating along the direction of the magnetic moment. This process is observed to be entirely reversible, offering external control over the emergent dynamics in dense chiral fluids, paving the way for new self-organization routes in chiral fluids and broader forms of active matter. Chiral active systems are composed of spinning constituent particles that self-organize into complex structures through hydrodynamic interactions. The authors develop methods to control these self-organized structures by introducing additional chemical interactions between spinning particles.
{"title":"Control of colloidal cohesive states in active chiral fluids","authors":"Jaideep Katuri, Navneet Kaur, William Uspal, Allison Cornelius, David Quashie Jr., Jamel Ali","doi":"10.1038/s42005-024-01787-3","DOIUrl":"10.1038/s42005-024-01787-3","url":null,"abstract":"Ensembles of suspended spinning particles in liquids form a distinct category of active matter systems known as chiral fluids. Recent experimental instances of dense chiral fluids have comprised of spinning colloidal magnets powered by an external rotating magnetic field. These particles interact through both magnetic and hydrodynamic forces, organizing collectively into circulating clusters characterized by unidirectional edge flows. Here, we externally drive the collective behavior of spinning colloids by leveraging diffusiophoretic interactions among the geometrically anisotropic particles. We show that these nanoscale interfacial flows lead to the formation of bound states between spinning colloids that are stabilized through near-field hydrodynamic and chemical interactions. At a collective level, we demonstrate that added diffusiophoretic interactions cause a loss in structural cohesion of the circulating clusters and promote expansion, while preserving global cluster inter-connectivity. The expanded cluster state is characterized by the formation of a dynamic interconnected network promoted by axi-asymmetric interactions around particles with attractive dipolar interactions dominating along the direction of the magnetic moment. This process is observed to be entirely reversible, offering external control over the emergent dynamics in dense chiral fluids, paving the way for new self-organization routes in chiral fluids and broader forms of active matter. Chiral active systems are composed of spinning constituent particles that self-organize into complex structures through hydrodynamic interactions. The authors develop methods to control these self-organized structures by introducing additional chemical interactions between spinning particles.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":null,"pages":null},"PeriodicalIF":5.4,"publicationDate":"2024-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01787-3.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142100551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-29DOI: 10.1038/s42005-024-01783-7
Zhihan Zhang, Weiyuan Gong, Weikang Li, Dong-Ling Deng
An essential problem in quantum machine learning is to find quantum-classical separations between learning models. However, rigorous and unconditional separations are lacking for supervised learning. Here we construct a classification problem defined by a noiseless constant depth (i.e., shallow) quantum circuit and rigorously prove that any classical neural network with bounded connectivity requires logarithmic depth to output correctly with a larger-than-exponentially-small probability. This unconditional near-optimal quantum-classical representation power separation originates from the quantum nonlocality property that distinguishes quantum circuits from their classical counterparts. We further characterize the noise regimes for demonstrating such a separation on near-term quantum devices under the depolarization noise model. In addition, for quantum devices with constant noise strength, we prove that no super-polynomial classical-quantum separation exists for any classification task defined by Clifford circuits, independent of the structures of the circuits that specify the learning models. An essential problem in quantum machine learning is to find quantum-classical separations between learning models. The authors construct a classification problem based on constant depth quantum circuit to rigorously prove that such a separation exists in terms of representation power, and further characterize the noise regimes for the separation to exist.
{"title":"Quantum-classical separations in shallow-circuit-based learning with and without noises","authors":"Zhihan Zhang, Weiyuan Gong, Weikang Li, Dong-Ling Deng","doi":"10.1038/s42005-024-01783-7","DOIUrl":"10.1038/s42005-024-01783-7","url":null,"abstract":"An essential problem in quantum machine learning is to find quantum-classical separations between learning models. However, rigorous and unconditional separations are lacking for supervised learning. Here we construct a classification problem defined by a noiseless constant depth (i.e., shallow) quantum circuit and rigorously prove that any classical neural network with bounded connectivity requires logarithmic depth to output correctly with a larger-than-exponentially-small probability. This unconditional near-optimal quantum-classical representation power separation originates from the quantum nonlocality property that distinguishes quantum circuits from their classical counterparts. We further characterize the noise regimes for demonstrating such a separation on near-term quantum devices under the depolarization noise model. In addition, for quantum devices with constant noise strength, we prove that no super-polynomial classical-quantum separation exists for any classification task defined by Clifford circuits, independent of the structures of the circuits that specify the learning models. An essential problem in quantum machine learning is to find quantum-classical separations between learning models. The authors construct a classification problem based on constant depth quantum circuit to rigorously prove that such a separation exists in terms of representation power, and further characterize the noise regimes for the separation to exist.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":null,"pages":null},"PeriodicalIF":5.4,"publicationDate":"2024-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01783-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142100554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-28DOI: 10.1038/s42005-024-01780-w
Leila Abbaspour, Rituparno Mandal, Peter Sollich, Stefan Klumpp
Active matter systems display collective behaviors that are impossible in thermodynamic equilibrium. One such feature, observed in in dense active matter systems is the appearance of long-range velocity correlations without explicit aligning interaction. However, the conditions for the appearance of these correlations remain largely unexplored. Here we show that such long-range velocity correlations can also be generated in a dense athermal passive system by the inclusion of a very small fraction of active Brownian particles. We develop a continuum theory to explain the emergence of velocity correlations generated via such active dopants. We validate the predictions for the effects of magnitude and persistence time of the active force and the area fractions of active and passive particles using extensive Brownian dynamics simulation of a canonical active-passive mixture. Our work decouples the roles that density and activity play in generating long-range velocity correlations in such exotic non-equilibrium steady states. Crowded systems of active particles show collective movement with pronounced velocity correlations. Using simulations and analytical theory, the authors show that very similar movement patterns with the same velocity correlations are found if a small number of randomly moving active particles is added to a dense system of passive particles.
{"title":"Long-range velocity correlations from active dopants","authors":"Leila Abbaspour, Rituparno Mandal, Peter Sollich, Stefan Klumpp","doi":"10.1038/s42005-024-01780-w","DOIUrl":"10.1038/s42005-024-01780-w","url":null,"abstract":"Active matter systems display collective behaviors that are impossible in thermodynamic equilibrium. One such feature, observed in in dense active matter systems is the appearance of long-range velocity correlations without explicit aligning interaction. However, the conditions for the appearance of these correlations remain largely unexplored. Here we show that such long-range velocity correlations can also be generated in a dense athermal passive system by the inclusion of a very small fraction of active Brownian particles. We develop a continuum theory to explain the emergence of velocity correlations generated via such active dopants. We validate the predictions for the effects of magnitude and persistence time of the active force and the area fractions of active and passive particles using extensive Brownian dynamics simulation of a canonical active-passive mixture. Our work decouples the roles that density and activity play in generating long-range velocity correlations in such exotic non-equilibrium steady states. Crowded systems of active particles show collective movement with pronounced velocity correlations. Using simulations and analytical theory, the authors show that very similar movement patterns with the same velocity correlations are found if a small number of randomly moving active particles is added to a dense system of passive particles.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":null,"pages":null},"PeriodicalIF":5.4,"publicationDate":"2024-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01780-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142100546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-24DOI: 10.1038/s42005-024-01782-8
Jinzhan Zhong, Houan Teng, Qiwen Zhan
Control of topologies in structured light fields with multi-degrees of freedom integrates fundamental optical physics and topological invariance. Beyond the simple phase vortex, three-dimensional (3D) topological singularities and related nonsingular textures have recently gained significant interest. Here, we experimentally demonstrate the creation of a family of toroidal phase topologies within paraxial laser beams. By employing single two-dimensional (2D) phase control, we generate propagating 3D topological textures, effectively embodying the topological configuration of a four-dimensional (4D) parameter space. The resulting light fields exhibit amplitude isosurfaces of toroidal vortices and hopfionic phase textures, both controlled by topological charges. The ability to prepare scalar phase textures of light offers new insights into the high-dimensional control of complex structured textures and may find significant applications in light-matter interactions, optical manipulation, and optical information encoding. Exploring non-trivial topologies and related properties has long been a fascinating and challenging task in mathematics and physics. The authors experimentally demonstrate the realization of optical toroidal vortices and hopfionic phase textures within paraxial continuous wave laser beams, which may provide new insight for topologically structured light fields.
{"title":"Toroidal phase topologies within paraxial laser beams","authors":"Jinzhan Zhong, Houan Teng, Qiwen Zhan","doi":"10.1038/s42005-024-01782-8","DOIUrl":"10.1038/s42005-024-01782-8","url":null,"abstract":"Control of topologies in structured light fields with multi-degrees of freedom integrates fundamental optical physics and topological invariance. Beyond the simple phase vortex, three-dimensional (3D) topological singularities and related nonsingular textures have recently gained significant interest. Here, we experimentally demonstrate the creation of a family of toroidal phase topologies within paraxial laser beams. By employing single two-dimensional (2D) phase control, we generate propagating 3D topological textures, effectively embodying the topological configuration of a four-dimensional (4D) parameter space. The resulting light fields exhibit amplitude isosurfaces of toroidal vortices and hopfionic phase textures, both controlled by topological charges. The ability to prepare scalar phase textures of light offers new insights into the high-dimensional control of complex structured textures and may find significant applications in light-matter interactions, optical manipulation, and optical information encoding. Exploring non-trivial topologies and related properties has long been a fascinating and challenging task in mathematics and physics. The authors experimentally demonstrate the realization of optical toroidal vortices and hopfionic phase textures within paraxial continuous wave laser beams, which may provide new insight for topologically structured light fields.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":null,"pages":null},"PeriodicalIF":5.4,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01782-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142058637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-24DOI: 10.1038/s42005-024-01778-4
Tania M. Barone, Glenn G. Kacprzak, James W. Nightingale, Nikole M. Nielsen, Karl Glazebrook, Kim-Vy H. Tran, Tucker Jones, Hasti Nateghi, Keerthi Vasan Gopala Chandrasekaran, Nandini Sahu, Themiya Nanayakkara, Hannah Skobe, Jesse van de Sande, Sebastian Lopez, Geraint F. Lewis
While quiescent galaxies have comparable amounts of cool gas in their outer circumgalactic medium (CGM) compared to star-forming galaxies, they have significantly less interstellar gas. However, open questions remain on the processes causing galaxies to stop forming stars and stay quiescent. Theories suggest dynamical interactions with the hot corona prevent cool gas from reaching the galaxy, therefore predicting the inner regions of quiescent galaxy CGMs are devoid of cool gas. However, there is a lack of understanding of the inner regions of CGMs due to the lack of spatial information in quasar-sightline methods. We present integral-field spectroscopy probing 10–20 kpc (2.4–4.8 Re) around a massive quiescent galaxy using a gravitationally lensed star-forming galaxy. We detect absorption from Magnesium (MgII) implying large amounts of cool atomic gas (108.4–109.3 M⊙ with T~104 Kelvin), in comparable amounts to star-forming galaxies. Lens modeling of Hubble imaging also reveals a diffuse asymmetric component of significant mass consistent with the spatial extent of the MgII absorption, and offset from the galaxy light profile. This study demonstrates the power of galaxy-scale gravitational lenses to not only probe the gas around galaxies, but to also independently probe the mass of the CGM due to it’s gravitational effect. Quiescent galaxies have similar amount of cool gas to star forming galaxies, yet why galaxies stop forming stars remains an open question. The authors investigate why passive galaxies remain quiescent using a gravitationally lensed background galaxy to probe the faint, diffuse cool gas around a massive quiescent galaxy, and use lensing configuration to constrain the total mass and geometry of this gas reservoir.
{"title":"Gravitational lensing reveals cool gas within 10-20 kpc around a quiescent galaxy","authors":"Tania M. Barone, Glenn G. Kacprzak, James W. Nightingale, Nikole M. Nielsen, Karl Glazebrook, Kim-Vy H. Tran, Tucker Jones, Hasti Nateghi, Keerthi Vasan Gopala Chandrasekaran, Nandini Sahu, Themiya Nanayakkara, Hannah Skobe, Jesse van de Sande, Sebastian Lopez, Geraint F. Lewis","doi":"10.1038/s42005-024-01778-4","DOIUrl":"10.1038/s42005-024-01778-4","url":null,"abstract":"While quiescent galaxies have comparable amounts of cool gas in their outer circumgalactic medium (CGM) compared to star-forming galaxies, they have significantly less interstellar gas. However, open questions remain on the processes causing galaxies to stop forming stars and stay quiescent. Theories suggest dynamical interactions with the hot corona prevent cool gas from reaching the galaxy, therefore predicting the inner regions of quiescent galaxy CGMs are devoid of cool gas. However, there is a lack of understanding of the inner regions of CGMs due to the lack of spatial information in quasar-sightline methods. We present integral-field spectroscopy probing 10–20 kpc (2.4–4.8 Re) around a massive quiescent galaxy using a gravitationally lensed star-forming galaxy. We detect absorption from Magnesium (MgII) implying large amounts of cool atomic gas (108.4–109.3 M⊙ with T~104 Kelvin), in comparable amounts to star-forming galaxies. Lens modeling of Hubble imaging also reveals a diffuse asymmetric component of significant mass consistent with the spatial extent of the MgII absorption, and offset from the galaxy light profile. This study demonstrates the power of galaxy-scale gravitational lenses to not only probe the gas around galaxies, but to also independently probe the mass of the CGM due to it’s gravitational effect. Quiescent galaxies have similar amount of cool gas to star forming galaxies, yet why galaxies stop forming stars remains an open question. The authors investigate why passive galaxies remain quiescent using a gravitationally lensed background galaxy to probe the faint, diffuse cool gas around a massive quiescent galaxy, and use lensing configuration to constrain the total mass and geometry of this gas reservoir.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":null,"pages":null},"PeriodicalIF":5.4,"publicationDate":"2024-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01778-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142058635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-22DOI: 10.1038/s42005-024-01764-w
Jennifer Coulter, Mark R. Hirsbrunner, Oleg Dubinkin, Taylor L. Hughes, Boris Kozinsky
The xene family of topological insulators plays a key role in many proposals for topological electronic, spintronic, and valleytronic devices. These proposals rely on applying local perturbations, including electric fields and proximity magnetism, to induce topological phase transitions in xenes. However, these techniques lack control over the geometry of interfaces between topological regions, a critical aspect of engineering topological devices. We propose adatom decoration as a method for engineering atomically precise topological edge modes in xenes. Our first-principles calculations show that decorating stanene with Zn adatoms exclusively on one of two sublattices induces a topological phase transition from the quantum spin Hall (QSH) to quantum valley Hall (QVH) phase and confirm the existence of spin-valley polarized edge modes propagating at QSH/QVH interfaces. We conclude by discussing technological applications of these edge modes that are enabled by the atomic precision afforded by recent advances in adatom manipulation technology. The authors propose sublattice-selective decoration by Zn adatoms as a method to engineer precise topological edge modes in xenes. First-principles calculations on Zn decorated stanene reveal a quantum spin Hall (QSH) to quantum valley Hall (QVH) transition and spin-valley polarized modes propagating at the QSH/QVH interface.
{"title":"Engineering ideal helical topological networks in stanene via Zn decoration","authors":"Jennifer Coulter, Mark R. Hirsbrunner, Oleg Dubinkin, Taylor L. Hughes, Boris Kozinsky","doi":"10.1038/s42005-024-01764-w","DOIUrl":"10.1038/s42005-024-01764-w","url":null,"abstract":"The xene family of topological insulators plays a key role in many proposals for topological electronic, spintronic, and valleytronic devices. These proposals rely on applying local perturbations, including electric fields and proximity magnetism, to induce topological phase transitions in xenes. However, these techniques lack control over the geometry of interfaces between topological regions, a critical aspect of engineering topological devices. We propose adatom decoration as a method for engineering atomically precise topological edge modes in xenes. Our first-principles calculations show that decorating stanene with Zn adatoms exclusively on one of two sublattices induces a topological phase transition from the quantum spin Hall (QSH) to quantum valley Hall (QVH) phase and confirm the existence of spin-valley polarized edge modes propagating at QSH/QVH interfaces. We conclude by discussing technological applications of these edge modes that are enabled by the atomic precision afforded by recent advances in adatom manipulation technology. The authors propose sublattice-selective decoration by Zn adatoms as a method to engineer precise topological edge modes in xenes. First-principles calculations on Zn decorated stanene reveal a quantum spin Hall (QSH) to quantum valley Hall (QVH) transition and spin-valley polarized modes propagating at the QSH/QVH interface.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":null,"pages":null},"PeriodicalIF":5.4,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01764-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142041753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-21DOI: 10.1038/s42005-024-01772-w
Grigorios P. Zouros, Iridanos Loulas, Evangelos Almpanis, Alex Krasnok, Kosmas L. Tsakmakidis
Active tuning of the scattering of particles and metasurfaces is a highly sought-after property for a host of electromagnetic and photonic applications, but it normally requires challenging-to-control tunable (reconfigurable) or active (gain) media. Here, we introduce the concepts of anisotropic virtual gain and oblique Kerker effect, where a completely lossy anisotropic medium behaves exactly as its anisotropic gain counterpart upon excitation by a synthetic complex-frequency wave. The strategy allows one to largely tune the magnitude and angle of a particle’s scattering simply by changing the shape (envelope) of the incoming radiation, rather than by an involved medium-tuning mechanism. The so-attained anisotropic virtual gain enables directional super-scattering at an oblique direction with fine-management of the scattering angle. Our study is based on analytical techniques that allow multipolar decomposition of the scattered field in agreement with full-wave simulations, and lays the foundations for a light management method. The authors show how the use of suitable time-domain pulses, characterized by a complex frequency, can turn anisotropic losses to anisotropic virtual gain in small particles. These excitations can largely tune the scattering off particles without requiring any other tuning mechanism.
{"title":"Anisotropic virtual gain and large tuning of particles’ scattering by complex-frequency excitations","authors":"Grigorios P. Zouros, Iridanos Loulas, Evangelos Almpanis, Alex Krasnok, Kosmas L. Tsakmakidis","doi":"10.1038/s42005-024-01772-w","DOIUrl":"10.1038/s42005-024-01772-w","url":null,"abstract":"Active tuning of the scattering of particles and metasurfaces is a highly sought-after property for a host of electromagnetic and photonic applications, but it normally requires challenging-to-control tunable (reconfigurable) or active (gain) media. Here, we introduce the concepts of anisotropic virtual gain and oblique Kerker effect, where a completely lossy anisotropic medium behaves exactly as its anisotropic gain counterpart upon excitation by a synthetic complex-frequency wave. The strategy allows one to largely tune the magnitude and angle of a particle’s scattering simply by changing the shape (envelope) of the incoming radiation, rather than by an involved medium-tuning mechanism. The so-attained anisotropic virtual gain enables directional super-scattering at an oblique direction with fine-management of the scattering angle. Our study is based on analytical techniques that allow multipolar decomposition of the scattered field in agreement with full-wave simulations, and lays the foundations for a light management method. The authors show how the use of suitable time-domain pulses, characterized by a complex frequency, can turn anisotropic losses to anisotropic virtual gain in small particles. These excitations can largely tune the scattering off particles without requiring any other tuning mechanism.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":null,"pages":null},"PeriodicalIF":5.4,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01772-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142041788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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