Delay-bandwidth product (DBP) is a key metric in slow light waveguides, requiring a balance between a large group index and broad bandwidth—two parameters that often involve a trade-off. Here, we propose and demonstrate a slow light waveguide with large DBP using a pseudospin-polarized transverse electromagnetic mode. This waveguide features a folded edge configuration that supports a 200% relative bandwidth from quasistatic limit (zero frequency) and an arbitrarily large group index. Owing to the pseudospin-polarized design, the dense folding would not introduce backscattering and the associated group velocity dispersion (GVD). The resulting gapless linear dispersion and pulse transmission behavior in folded edge waveguide are observed in microwave experiments. Our scheme provides a way to overcome the trade-off between group index and working bandwidth in slow light waveguide, which has potential applications in broadband optical buffering, light-matter interaction enhancement, terahertz radiation source and time domain processing. Delay-bandwidth product (DBP), which require a large group index and a wide bandwidth, is an important indicator in slow light waveguides. This work relaxes the trade-off between group velocity and working bandwidth in 200% relative bandwidth, and realizes a pseudospin-polarized slow-light waveguide with large DBP and low group velocity dispersion.
{"title":"Pseudospin-polarized slow light waveguides with large delay-bandwidth product","authors":"Fu-Long Shi, Xiao-Dong Chen, Wen-Jie Chen, Jian-Wen Dong","doi":"10.1038/s42005-024-01853-w","DOIUrl":"10.1038/s42005-024-01853-w","url":null,"abstract":"Delay-bandwidth product (DBP) is a key metric in slow light waveguides, requiring a balance between a large group index and broad bandwidth—two parameters that often involve a trade-off. Here, we propose and demonstrate a slow light waveguide with large DBP using a pseudospin-polarized transverse electromagnetic mode. This waveguide features a folded edge configuration that supports a 200% relative bandwidth from quasistatic limit (zero frequency) and an arbitrarily large group index. Owing to the pseudospin-polarized design, the dense folding would not introduce backscattering and the associated group velocity dispersion (GVD). The resulting gapless linear dispersion and pulse transmission behavior in folded edge waveguide are observed in microwave experiments. Our scheme provides a way to overcome the trade-off between group index and working bandwidth in slow light waveguide, which has potential applications in broadband optical buffering, light-matter interaction enhancement, terahertz radiation source and time domain processing. Delay-bandwidth product (DBP), which require a large group index and a wide bandwidth, is an important indicator in slow light waveguides. This work relaxes the trade-off between group velocity and working bandwidth in 200% relative bandwidth, and realizes a pseudospin-polarized slow-light waveguide with large DBP and low group velocity dispersion.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-7"},"PeriodicalIF":5.4,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01853-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142566002","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 : 2024-11-02DOI: 10.1038/s42005-024-01847-8
Harindranath B. Ambalampitiya, J. M. Ngoko Djiokap
The discovery and measurements of symmetric normal Archimedean spirals from atomic ionization by a pair of time-delayed broadband oppositely circularly polarized pulses revealed their potential of discerning orbital symmetry in atoms. Transferring this tool to molecules substantially increases experimental and theoretical challenges. Here, we show how Einstein’s photoelectric effect bypasses the congestion of electronic intermediate states and can access the orbital symmetry in heteronuclear, multi-orbital aligned molecules. Thanks to the broad bandwidth, multi-orbital ionization leads to multiplexed molecular-frame photoelectron momentum distributions, hiding thus any molecular orbital information. Only when molecular orientation is used to manipulate the ionization channels that one can identify a robust doorway into the molecular quantum world in which the asymmetry inherent to the highest-occupied molecular orbital can be unambiguously revealed by the asymmetric molecular spirals from single-color pulses. Our results demonstrate the potential of polarization-tailored attopulse sequences for the retrieval of spectroscopic details on molecular orbital symmetries. For pulse bandwidth larger than the energy gap between molecular orbitals, distinguishing contributions of electrons photoionized from different orbitals is a major hurdle. Here, the authors mitigate this issue by rotating light with respect to the molecular axis and show that asymmetric spirals are a new source of information for molecular orbital symmetries.
{"title":"Orientation-dependent production of normal Archimedean and dynamical spirals for revealing orbital symmetries in diatomic multi-orbital molecules","authors":"Harindranath B. Ambalampitiya, J. M. Ngoko Djiokap","doi":"10.1038/s42005-024-01847-8","DOIUrl":"10.1038/s42005-024-01847-8","url":null,"abstract":"The discovery and measurements of symmetric normal Archimedean spirals from atomic ionization by a pair of time-delayed broadband oppositely circularly polarized pulses revealed their potential of discerning orbital symmetry in atoms. Transferring this tool to molecules substantially increases experimental and theoretical challenges. Here, we show how Einstein’s photoelectric effect bypasses the congestion of electronic intermediate states and can access the orbital symmetry in heteronuclear, multi-orbital aligned molecules. Thanks to the broad bandwidth, multi-orbital ionization leads to multiplexed molecular-frame photoelectron momentum distributions, hiding thus any molecular orbital information. Only when molecular orientation is used to manipulate the ionization channels that one can identify a robust doorway into the molecular quantum world in which the asymmetry inherent to the highest-occupied molecular orbital can be unambiguously revealed by the asymmetric molecular spirals from single-color pulses. Our results demonstrate the potential of polarization-tailored attopulse sequences for the retrieval of spectroscopic details on molecular orbital symmetries. For pulse bandwidth larger than the energy gap between molecular orbitals, distinguishing contributions of electrons photoionized from different orbitals is a major hurdle. Here, the authors mitigate this issue by rotating light with respect to the molecular axis and show that asymmetric spirals are a new source of information for molecular orbital symmetries.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-14"},"PeriodicalIF":5.4,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01847-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142566003","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 : 2024-10-31DOI: 10.1038/s42005-024-01839-8
Jean L. Rintoul, Esra Neufeld, Chris Butler, Robin O. Cleveland, Nir Grossman
{"title":"Author Correction: Remote focused encoding and decoding of electric fields through acoustoelectric heterodyning","authors":"Jean L. Rintoul, Esra Neufeld, Chris Butler, Robin O. Cleveland, Nir Grossman","doi":"10.1038/s42005-024-01839-8","DOIUrl":"10.1038/s42005-024-01839-8","url":null,"abstract":"","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-1"},"PeriodicalIF":5.4,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01839-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142555302","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}
Quantum teleportation is the process of transferring quantum information using classical communication and pre-shared entanglement. This process can benefit from the use of catalysts, which are ancillary entangled states that can enhance teleportation without being consumed. While chemical catalysts undergoing deactivation invariably exhibit inferior performance compared to those unaffected by deactivation, quantum catalysts, termed embezzling catalysts, that are subject to deactivation, may outperform their non-deactivating counterparts. In this work, we present teleportation protocols with embezzling catalysts that can achieve arbitrarily high fidelity. This enables the teleported state to closely approximate the original message state with arbitrary precision, while maintaining arbitrarily small variations in the catalytic system through the use of finite-dimensional embezzling catalysts. We show that some embezzling catalysts are universal, meaning that they can improve the teleportation fidelity for any pre-shared entanglement. We also explore methods to reduce the dimension of catalysts without increasing catalyst consumption, an essential step towards realizing quantum catalysis in practice. Quantum teleportation offers superior performance in transmitting information over classical methods but is often hindered by environmental noise. To address this issue, the authors introduce a teleportation protocol with finite-dimensional embezzling catalysts to achieve arbitrarily high fidelity, with only negligible changes to the catalytic systems.
{"title":"Teleportation with embezzling catalysts","authors":"Junjing Xing, Yuqi Li, Dengke Qu, Lei Xiao, Zhaobing Fan, Haitao Ma, Peng Xue, Kishor Bharti, Dax Enshan Koh, Yunlong Xiao","doi":"10.1038/s42005-024-01828-x","DOIUrl":"10.1038/s42005-024-01828-x","url":null,"abstract":"Quantum teleportation is the process of transferring quantum information using classical communication and pre-shared entanglement. This process can benefit from the use of catalysts, which are ancillary entangled states that can enhance teleportation without being consumed. While chemical catalysts undergoing deactivation invariably exhibit inferior performance compared to those unaffected by deactivation, quantum catalysts, termed embezzling catalysts, that are subject to deactivation, may outperform their non-deactivating counterparts. In this work, we present teleportation protocols with embezzling catalysts that can achieve arbitrarily high fidelity. This enables the teleported state to closely approximate the original message state with arbitrary precision, while maintaining arbitrarily small variations in the catalytic system through the use of finite-dimensional embezzling catalysts. We show that some embezzling catalysts are universal, meaning that they can improve the teleportation fidelity for any pre-shared entanglement. We also explore methods to reduce the dimension of catalysts without increasing catalyst consumption, an essential step towards realizing quantum catalysis in practice. Quantum teleportation offers superior performance in transmitting information over classical methods but is often hindered by environmental noise. To address this issue, the authors introduce a teleportation protocol with finite-dimensional embezzling catalysts to achieve arbitrarily high fidelity, with only negligible changes to the catalytic systems.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-16"},"PeriodicalIF":5.4,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01828-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142555510","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}
The fundamental principle of satellite/node-based positioning involves triangulating the receiver’s coordinates through the intersection of spatial distances. Advancements in hybrid wireless networks have yielded high-precision positioning at decimeter-level (wavelength-level), approaching the resolution limits in free space. Here we present a 3D super-resolution positioning paradigm in free space by utilizing a kind of topologically structured pulses, toroidal electromagnetic pulses. We demonstrate that the space-time nonseparability and skyrmion topology inherent in toroidal pulses can be harnessed to achieve freespace microwave 3D positioning with super-resolution accuracy, reaching the centimeter level, using a single emitting antenna. This work opens up avenues for exploring the potential applications of topological electromagnetic pulses including but not limited to positioning, imaging and sensing technologies. This paper presents a positioning paradigm in free space by utilizing toroidal electromagnetic pulses. The space-time nonseparability and skyrmion topology inherent in toroidal pulses are harnessed to achieve freespace microwave 3D positioning with super-resolution accuracy, reaching the centimeter level, using a single emitting antenna.
{"title":"Single-antenna super-resolution positioning with nonseparable toroidal pulses","authors":"Ren Wang, Pan-Yi Bao, Xiaoyu Feng, Junpu Wu, Bing-Zhong Wang, Yijie Shen","doi":"10.1038/s42005-024-01850-z","DOIUrl":"10.1038/s42005-024-01850-z","url":null,"abstract":"The fundamental principle of satellite/node-based positioning involves triangulating the receiver’s coordinates through the intersection of spatial distances. Advancements in hybrid wireless networks have yielded high-precision positioning at decimeter-level (wavelength-level), approaching the resolution limits in free space. Here we present a 3D super-resolution positioning paradigm in free space by utilizing a kind of topologically structured pulses, toroidal electromagnetic pulses. We demonstrate that the space-time nonseparability and skyrmion topology inherent in toroidal pulses can be harnessed to achieve freespace microwave 3D positioning with super-resolution accuracy, reaching the centimeter level, using a single emitting antenna. This work opens up avenues for exploring the potential applications of topological electromagnetic pulses including but not limited to positioning, imaging and sensing technologies. This paper presents a positioning paradigm in free space by utilizing toroidal electromagnetic pulses. The space-time nonseparability and skyrmion topology inherent in toroidal pulses are harnessed to achieve freespace microwave 3D positioning with super-resolution accuracy, reaching the centimeter level, using a single emitting antenna.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-6"},"PeriodicalIF":5.4,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01850-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142555536","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 : 2024-10-28DOI: 10.1038/s42005-024-01842-z
Zichen Li, Bofeng Zhu, Ying Li, Yihao Yang, Yidong Chong, Qi Jie Wang, Hongsheng Chen, Song Han
Beam shaping and polarization manipulation are of great importance for the design of microcavity lasers. Recently, topological photonic cavities have emerged as excellent platforms for surface-emitting lasers. In this class of lasers, beam engineering has not thus far been extensively studied. Here, we demonstrate how to achieve an intrinsic lateral shift of the beam emitted by a topological laser. This is achieved by designing a Kekulé-modulated topological bulk cavity, in which the continuous Kekulé modulation partially lifts a set of fourfold-degenerate Dirac cones into two twofold degeneracies. The resulting photonic cavity supports a range of interesting beam emission profiles, including vector beams with polarization winding, and laterally-shifted linearly-polarized Gaussian beams. It is possible to achieve lateral beam shifts in opposite directions and orthogonal polarizations for the degenerate photonic p-/d-orbitals, a feature that may be useful for photonic sensing applications. Topological phenomena in photonics have been found of great importance in realizing advanced semiconductor laser. Here the authors demonstrate the manipulation of the light emission profiles from a Kekulé-modulated topological bulk cavity in a topological-protection manner, where the achieved lateral beam shifts in light polarizations could be useful for the laser design and photonic sensing applications.
{"title":"Kekulé-modulated topological bulk cavity for intrinsic lateral beam shifting of high-purity linear-polarized light emission","authors":"Zichen Li, Bofeng Zhu, Ying Li, Yihao Yang, Yidong Chong, Qi Jie Wang, Hongsheng Chen, Song Han","doi":"10.1038/s42005-024-01842-z","DOIUrl":"10.1038/s42005-024-01842-z","url":null,"abstract":"Beam shaping and polarization manipulation are of great importance for the design of microcavity lasers. Recently, topological photonic cavities have emerged as excellent platforms for surface-emitting lasers. In this class of lasers, beam engineering has not thus far been extensively studied. Here, we demonstrate how to achieve an intrinsic lateral shift of the beam emitted by a topological laser. This is achieved by designing a Kekulé-modulated topological bulk cavity, in which the continuous Kekulé modulation partially lifts a set of fourfold-degenerate Dirac cones into two twofold degeneracies. The resulting photonic cavity supports a range of interesting beam emission profiles, including vector beams with polarization winding, and laterally-shifted linearly-polarized Gaussian beams. It is possible to achieve lateral beam shifts in opposite directions and orthogonal polarizations for the degenerate photonic p-/d-orbitals, a feature that may be useful for photonic sensing applications. Topological phenomena in photonics have been found of great importance in realizing advanced semiconductor laser. Here the authors demonstrate the manipulation of the light emission profiles from a Kekulé-modulated topological bulk cavity in a topological-protection manner, where the achieved lateral beam shifts in light polarizations could be useful for the laser design and photonic sensing applications.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-6"},"PeriodicalIF":5.4,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01842-z.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142525745","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 : 2024-10-28DOI: 10.1038/s42005-024-01836-x
Spencer Walker, Alexandra S. Landsman
This study delves into the relatively uncharted territory of Above Threshold Ionization in atoms, triggered by intense X-ray radiation fields. At these frequencies, the energy of a single photon far exceeds the ionization potential of valence electrons in atoms and molecules. The conditions we examine are similar to those achievable with current or future free-electron laser facilities. Under such high-energy scenarios, the onset of strong field ionization requires a shift away from the traditional quasi-classical approach. Here, we present an analytical model to characterize how the field-free ionization potential, ponderomotive energy, and photon energy govern the transition to this regime, all accounted for by means of the Keldysh and Reiss parameters. We show that both of these parameters are needed to capture the onset of strong-field behavior due to both bound state and continuum state properties. At higher X-ray intensities, we find that ionization rates deviate from the linear intensity scaling expected from lowest order perturbative processes, corresponding to channel closure and higher-order photon absorption processes. This study explores Above Threshold Ionization in atoms induced by intense X-ray radiation fields, where photon energy surpasses the ionization potential of valence electrons. The authors demonstrate that both the Keldysh and Reiss parameters are essential to capture the onset of strong-field behavior, revealing deviations from weak-field intensity scaling at higher X-ray intensities.
这项研究深入探讨了由强 X 射线辐射场引发的原子阈值以上电离这一相对未知的领域。在这些频率下，单个光子的能量远远超过了原子和分子中价电子的电离势。我们所研究的条件与当前或未来的自由电子激光设备所能达到的条件类似。在这种高能情况下，强场电离的发生需要摆脱传统的准经典方法。在此，我们提出了一个分析模型，以描述无场电离势、思索动能和光子能量如何支配向这一机制的过渡，所有这些都通过凯尔迪什参数和雷斯参数来说明。我们发现，由于束缚态和连续态的特性，需要这两个参数来捕捉强场行为的发生。在更高的 X 射线强度下，我们发现电离率偏离了最低阶扰动过程所预期的线性强度比例，这与通道关闭和高阶光子吸收过程相对应。这项研究探讨了强 X 射线辐射场诱导的原子阈值以上电离，在这种情况下，光子能量超过了价电子的电离势。作者证明了凯尔迪什参数和雷斯参数对于捕捉强场行为的发生至关重要，揭示了在较高 X 射线强度下与弱场强度缩放的偏差。
{"title":"Above-threshold ionization with X-ray free-electron lasers","authors":"Spencer Walker, Alexandra S. Landsman","doi":"10.1038/s42005-024-01836-x","DOIUrl":"10.1038/s42005-024-01836-x","url":null,"abstract":"This study delves into the relatively uncharted territory of Above Threshold Ionization in atoms, triggered by intense X-ray radiation fields. At these frequencies, the energy of a single photon far exceeds the ionization potential of valence electrons in atoms and molecules. The conditions we examine are similar to those achievable with current or future free-electron laser facilities. Under such high-energy scenarios, the onset of strong field ionization requires a shift away from the traditional quasi-classical approach. Here, we present an analytical model to characterize how the field-free ionization potential, ponderomotive energy, and photon energy govern the transition to this regime, all accounted for by means of the Keldysh and Reiss parameters. We show that both of these parameters are needed to capture the onset of strong-field behavior due to both bound state and continuum state properties. At higher X-ray intensities, we find that ionization rates deviate from the linear intensity scaling expected from lowest order perturbative processes, corresponding to channel closure and higher-order photon absorption processes. This study explores Above Threshold Ionization in atoms induced by intense X-ray radiation fields, where photon energy surpasses the ionization potential of valence electrons. The authors demonstrate that both the Keldysh and Reiss parameters are essential to capture the onset of strong-field behavior, revealing deviations from weak-field intensity scaling at higher X-ray intensities.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-16"},"PeriodicalIF":5.4,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01836-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142525697","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 : 2024-10-28DOI: 10.1038/s42005-024-01825-0
Pranava K. Sivakumar, Mostafa T. Ahari, Jae-Keun Kim, Yufeng Wu, Anvesh Dixit, George J. de Coster, Avanindra K. Pandeya, Matthew J. Gilbert, Stuart S. P. Parkin
Superconducting diode effects have recently attracted much attention for their potential applications in superconducting logic circuits. Several pathways have been proposed to give rise to non-reciprocal critical currents in various superconductors and Josephson junctions. In this work, we establish the presence of a large Josephson diode effect in a type-II Dirac semimetal 1T-PtTe2 facilitated by its helical spin-momentum locking and distinguish it from extrinsic geometric effects. The magnitude of the Josephson diode effect is shown to be directly correlated to the large second-harmonic component of the supercurrent. We denote such junctions, where the relative phase between the two harmonics can be tuned by a magnetic field, as ‘tunable second order φ0-junctions’. The direct correspondence between the second harmonic supercurrents and the diode effect in 1T-PtTe2 junctions at relatively low magnetic fields makes it an ideal platform to study the Josephson diode effect and Cooper quartet transport in Josephson junctions. This work reports on the observation of a large Josephson diode effect in a type-II Dirac semimetal 1T-PtTe2. The magnitude of the Josephson diode effect is found to be related to an asymmetry of the critical supercurrent which is modeled as a phase shift between the first and second harmonic terms of the current-phase relationship and can be tuned by an external magnetic field.
超导二极管效应最近因其在超导逻辑电路中的潜在应用而备受关注。在各种超导体和约瑟夫森结中，已经提出了几种产生非互易临界电流的途径。在这项研究中，我们证实了在 II 型狄拉克半金属 1T-PtTe2 中存在由其螺旋自旋动量锁定促进的巨大约瑟夫森二极管效应，并将其与外在几何效应区分开来。约瑟夫森二极管效应的大小与超电流的大二次谐波分量直接相关。我们将这样的结称为 "可调谐二阶φ0 结"，其中两个谐波之间的相对相位可通过磁场进行调谐。在相对较低的磁场下，1T-PtTe2 结中的二次谐波超电流与二极管效应之间的直接对应关系，使其成为研究约瑟夫森二极管效应和约瑟夫森结中库珀四元组输运的理想平台。这项研究报告了在 II 型狄拉克半金属 1T-PtTe2 中观察到的巨大约瑟夫森二极管效应。研究发现，约瑟夫森二极管效应的大小与临界超电流的不对称有关，而临界超电流被模拟为电流相位关系中一次谐波项和二次谐波项之间的相移，并可通过外部磁场进行调节。
{"title":"Long-range phase coherence and tunable second order φ0-Josephson effect in a Dirac semimetal 1T-PtTe2","authors":"Pranava K. Sivakumar, Mostafa T. Ahari, Jae-Keun Kim, Yufeng Wu, Anvesh Dixit, George J. de Coster, Avanindra K. Pandeya, Matthew J. Gilbert, Stuart S. P. Parkin","doi":"10.1038/s42005-024-01825-0","DOIUrl":"10.1038/s42005-024-01825-0","url":null,"abstract":"Superconducting diode effects have recently attracted much attention for their potential applications in superconducting logic circuits. Several pathways have been proposed to give rise to non-reciprocal critical currents in various superconductors and Josephson junctions. In this work, we establish the presence of a large Josephson diode effect in a type-II Dirac semimetal 1T-PtTe2 facilitated by its helical spin-momentum locking and distinguish it from extrinsic geometric effects. The magnitude of the Josephson diode effect is shown to be directly correlated to the large second-harmonic component of the supercurrent. We denote such junctions, where the relative phase between the two harmonics can be tuned by a magnetic field, as ‘tunable second order φ0-junctions’. The direct correspondence between the second harmonic supercurrents and the diode effect in 1T-PtTe2 junctions at relatively low magnetic fields makes it an ideal platform to study the Josephson diode effect and Cooper quartet transport in Josephson junctions. This work reports on the observation of a large Josephson diode effect in a type-II Dirac semimetal 1T-PtTe2. The magnitude of the Josephson diode effect is found to be related to an asymmetry of the critical supercurrent which is modeled as a phase shift between the first and second harmonic terms of the current-phase relationship and can be tuned by an external magnetic field.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-12"},"PeriodicalIF":5.4,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01825-0.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142525708","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}
Quantum networks typically comprise quantum channels, repeaters, and end nodes. Remote state preparation (RSP) allows one end node to prepare the states of the other end nodes remotely. While quantum discord has recently been recognized as necessary for RSP, it does not guarantee the practical implementation of RSP in quantum networks surpasses any classical method. Herein, we theoretically introduce and experimentally study a quantum resource that we call the RSP capability. This resource validates all the static and dynamic elements required to enable genuine quantum networks where the RSP’s implementation can outperform any classical emulation of entanglement- and qubit-unitaries-free strategies, including the static resources of Einstein-Podolsky-Rosen pairs and the dynamic resources of quantum channels and repeaters. Our experiment measures the RSP capability to demonstrate the transition between classical and nonclassical RSP depending on the photon-pair qualities. It shows that quantum discord does not confirm a nonclassical RSP, but the RSP capability does. These results help reveal the quantum advantages that emerge when networking RSP is in play. The authors introduce and experimentally study a quantum resource called the remote state preparation capability. This resource validates all static and dynamic elements required to enable quantum networks where the implementation of remote state preparation can outperform any classical emulation of entanglement- and qubit-unitaries-free strategies.
{"title":"Preparing remote states for genuine quantum networks","authors":"Shih-Hsuan Chen, Chan Hsu, Yu-Chien Kao, Bing-Yuan Lee, Yuan-Sung Liu, Yueh-Nan Chen, Che-Ming Li","doi":"10.1038/s42005-024-01844-x","DOIUrl":"10.1038/s42005-024-01844-x","url":null,"abstract":"Quantum networks typically comprise quantum channels, repeaters, and end nodes. Remote state preparation (RSP) allows one end node to prepare the states of the other end nodes remotely. While quantum discord has recently been recognized as necessary for RSP, it does not guarantee the practical implementation of RSP in quantum networks surpasses any classical method. Herein, we theoretically introduce and experimentally study a quantum resource that we call the RSP capability. This resource validates all the static and dynamic elements required to enable genuine quantum networks where the RSP’s implementation can outperform any classical emulation of entanglement- and qubit-unitaries-free strategies, including the static resources of Einstein-Podolsky-Rosen pairs and the dynamic resources of quantum channels and repeaters. Our experiment measures the RSP capability to demonstrate the transition between classical and nonclassical RSP depending on the photon-pair qualities. It shows that quantum discord does not confirm a nonclassical RSP, but the RSP capability does. These results help reveal the quantum advantages that emerge when networking RSP is in play. The authors introduce and experimentally study a quantum resource called the remote state preparation capability. This resource validates all static and dynamic elements required to enable quantum networks where the implementation of remote state preparation can outperform any classical emulation of entanglement- and qubit-unitaries-free strategies.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-10"},"PeriodicalIF":5.4,"publicationDate":"2024-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01844-x.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142525719","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 : 2024-10-26DOI: 10.1038/s42005-024-01840-1
Cheng-Lin Lv, Zhong-Yi Li, Shi-Da Wang, Bo Li
Tissue interfaces are essential for development and their disruption often leads to diseases such as tumor invasion. Here, we combine experiments, theoretical modeling, and numerical simulations to quantify the morphodynamics of interface in a biphasic system composed of Madin Darby canine kidney (MDCK) and mouse myoblast (C2C12) cells. We show that cellular activity regulates the interface morphodynamics and drives wave propagation along the interface. Based on the dispersion relationship, we identify that the wave dynamics results from the activity-mediated instability of the interface and coherent flow. It is found that the topological defects accumulate around and destabilize the interface and +1/2 topological defects are more likely to aggregate in MDCK cell clusters. A biphasic active nematic theory is employed to reproduce our experimental observations and decipher the underlying mechanisms. These findings provide physical insights into the interfacial evolution that could be implicated in tissue morphogenesis and tumor invasion. Interfaces are ubiquitous in living systems and play pivotal roles in physiological and pathological processes. The authors combine experiments and numerical simulations to investigate morphodynamics of the interface between dissimilar cell aggregations.
{"title":"Morphodynamics of interface between dissimilar cell aggregations","authors":"Cheng-Lin Lv, Zhong-Yi Li, Shi-Da Wang, Bo Li","doi":"10.1038/s42005-024-01840-1","DOIUrl":"10.1038/s42005-024-01840-1","url":null,"abstract":"Tissue interfaces are essential for development and their disruption often leads to diseases such as tumor invasion. Here, we combine experiments, theoretical modeling, and numerical simulations to quantify the morphodynamics of interface in a biphasic system composed of Madin Darby canine kidney (MDCK) and mouse myoblast (C2C12) cells. We show that cellular activity regulates the interface morphodynamics and drives wave propagation along the interface. Based on the dispersion relationship, we identify that the wave dynamics results from the activity-mediated instability of the interface and coherent flow. It is found that the topological defects accumulate around and destabilize the interface and +1/2 topological defects are more likely to aggregate in MDCK cell clusters. A biphasic active nematic theory is employed to reproduce our experimental observations and decipher the underlying mechanisms. These findings provide physical insights into the interfacial evolution that could be implicated in tissue morphogenesis and tumor invasion. Interfaces are ubiquitous in living systems and play pivotal roles in physiological and pathological processes. The authors combine experiments and numerical simulations to investigate morphodynamics of the interface between dissimilar cell aggregations.","PeriodicalId":10540,"journal":{"name":"Communications Physics","volume":" ","pages":"1-11"},"PeriodicalIF":5.4,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s42005-024-01840-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142525742","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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