期刊文献+
共找到17篇文章
< 1 >
每页显示 20 50 100
A Unifying Theory of Dark Energy, Dark Matter, and Baryonic Matter in the Positive-Negative Mass Universe Pair: Protogalaxy and Galaxy Evolutions
1
作者 Ding-Yu Chung 《Journal of Modern Physics》 2020年第7期1091-1122,共32页
This paper modifies the Farnes’ unifying theory of dark energy and dark matter which are negative-mass, created continuously from the negative-mass universe in the positive-negative mass universe pair. The first modi... This paper modifies the Farnes’ unifying theory of dark energy and dark matter which are negative-mass, created continuously from the negative-mass universe in the positive-negative mass universe pair. The first modification explains that observed dark energy is 68.6%, greater than 50% for the symmetrical positive-negative mass universe pair. This paper starts with the proposed positive-negative-mass 11D universe pair (without kinetic energy) which is transformed into the positive-negative mass 10D universe pair and the external dual gravities as in the Randall-Sundrum model, resulting in the four equal and separate universes consisting of the positive-mass 10D universe, the positive-mass massive external gravity, the negative-mass 10D universe and the negative-mass massive external gravity. The positive-mass 10D universe is transformed into 4D universe (home universe) with kinetic energy through the inflation and the Big Bang to create positive-mass dark matter which is five times of positive-mass baryonic matter. The other three universes without kinetic energy oscillate between 10D and 10D through 4D, resulting in the hidden universes when D > 4 and dark energy when D = 4, which is created continuously to our 4D home universe with the maximum dark energy = 3/4 = 75%. In the second modification to explain dark matter in the CMB, dark matter initially is not repulsive. The condensed baryonic gas at the critical surface density induces dark matter repulsive force to transform dark matter in the region into repulsive dark matter repulsing one another. The calculated percentages of dark energy, dark matter, and baryonic matter are 68.6 (as an input from the observation), 26 and 5.2, respectively, in agreement with observed 68.6, 26.5 and 4.9, respectively, and dark energy started in 4.33 billion years ago in agreement with the observed 4.71 <span style="white-space:nowrap;">&plusmn;</span> 0.98 billion years ago. In conclusion, the modified Farnes’ unifying theory reinterprets the Farnes’ equations, and is a unifying theory of dark energy, dark matter, and baryonic matter in the positive-negative mass universe pair. The unifying theory explains protogalaxy and galaxy evolutions in agreement with the observations. 展开更多
关键词 Unifying Theory Farnes Dark Energy Dark Matter Baryonic Matter negative mass Positive-negative mass Universe Pair Protogalaxy Evolution Galaxy Evolution
下载PDF
Resolving Electron Mass Inconsistency Using Negative Mass
2
作者 Arlen Young 《Journal of Modern Physics》 CAS 2022年第9期1287-1294,共8页
In a previous publication, the author discussed the electron mass and charge inconsistencies resulting from classical models. A model was proposed using classical equations and two opposite charges to resolve the char... In a previous publication, the author discussed the electron mass and charge inconsistencies resulting from classical models. A model was proposed using classical equations and two opposite charges to resolve the charge inconsistency. The model proposed in that article is modified herein using classical equations to define a model that also resolves the mass inconsistency. The positive mass of the outer shell of the electron core is replaced with a negative mass. The small negatively-charged core at the center still has positive mass. 展开更多
关键词 Classical Electron Model Electron Radius Electron Magnetic Dipole Moment Electron Spin Angular Momentum negative mass Electron mass Inconsistency Electron Charge Inconsistency Particle Physics
下载PDF
Is the Higgs Field a Positive and Negative Mass Planckion Condensate, and Does the LHC Produce Extreme Dark Energy?
3
作者 Christopher Pilot 《Journal of High Energy Physics, Gravitation and Cosmology》 2022年第2期432-456,共25页
Assuming a two-component, positive and negative mass, superfluid/supersolid for space (the Winterberg model), we model the Higgs field as a condensate made up of a positive and a negative mass, planckion pair. The con... Assuming a two-component, positive and negative mass, superfluid/supersolid for space (the Winterberg model), we model the Higgs field as a condensate made up of a positive and a negative mass, planckion pair. The connection is shown to be consistent (compatible) with the underlying field equations for each field, and the continuity equation is satisfied for both species of planckions, as well as for the Higgs field. An inherent length scale for space (the vacuum) emerges, which we estimate from previous work to be of the order of, l<sub>+</sub> (0) = l<sub>-</sub> (0) = 5.032E-19 meters, for an undisturbed (unperturbed) vacuum. Thus we assume a lattice structure for space, made up of overlapping positive and negative mass wave functions, ψ<sub>+</sub>, and, ψ<sub>-</sub>, which together bind to form the Higgs field, giving it its rest mass of 125.35 Gev/c<sup>2</sup> with a coherence length equal to its Compton wavelength. If the vacuum experiences an extreme disturbance, such as in a LHC pp collision, it is conjectured that severe dark energy results, on a localized level, with a partial disintegration of the Higgs force field in the surrounding space. The Higgs boson as a quantum excitation in this field results when the vacuum reestablishes itself, within 10<sup>-22</sup> seconds, with positive and negative planckion mass number densities equalizing in the disturbed region. Using our fundamental equation relating the Higgs field, φ, to the planckion ψ<sub>+</sub> and ψ<sub>-</sub> wave functions, we calculate the overall vacuum pressure (equal to vacuum energy density), as well as typical ψ<sub>+</sub> and ψ<sub>-</sub> displacements from equilibrium within the vacuum. 展开更多
关键词 Winterberg Model Quantum Vacuum Higgs Condensate/Composite Model Two-Component Superfluid/Supersolid Model for the Vacuum Positive/negative Planckion mass Q-Theory Non-Linear Heisenberg Spinor Theory LHC Energies Dark Energy Lattice Substructure for Space
下载PDF
Electron Shape Calculated for the Dual-Charge Dual-Mass Model
4
作者 Arlen Young 《Journal of Modern Physics》 CAS 2023年第3期198-207,共10页
A model for the internal structure of the electron using classical physics equations has been previously published by the author. The model employs both positive and negative charges and positive and negative masses. ... A model for the internal structure of the electron using classical physics equations has been previously published by the author. The model employs both positive and negative charges and positive and negative masses. The internal attributes of the electron structure were calculated for both ring and spherical shapes. Further examination of the model reveals an instability for the ring shape. The spherical shape appears to be stable, but relies on tensile or compressive forces of the electron material for stability. The model is modified in this document to eliminate the dependency on material forces. Uniform stability is provided solely by balancing electrical and centrifugal forces. This stability is achieved by slightly elongating the sphere along the spin axis to create a prolate ellipsoid. The semi-major axis of the ellipsoid is the spin axis of the electron, and is calculated to be 1.20% longer than the semi-minor axis, which is the radius of the equator. Although the shape deviates slightly from a perfect sphere, the electric dipole moment is zero. In the author’s previously published document, the attributes of the internal components of the electron, such as charge and mass, were calculated and expressed as ratios to the classically measured values for the composite electron. It is interesting to note that all of these ratios are nearly the same as the inverse of the Fine Structure Constant, with differences of less than 15%. The electron model assumed that the outer surface charge was fixed and uniform. By allowing the charge to be mobile and the shape to have a particular ellipticity, it is shown that the calculated charge and mass ratios for the model can be exactly equal to the Fine Structure Constant and the Constant plus one. The electron radius predicted by the model is 15% greater than the Classical Electron Radius. 展开更多
关键词 Electron Shape Classical Electron Model Dual-Charge Dual-mass Model Electron Radius negative mass Electron mass Inconsistency Electron Charge Inconsistency Fine Structure Constant
下载PDF
An Electron Model Based on the Fine Structure Constant
5
作者 Arlen Young 《Journal of Modern Physics》 CAS 2023年第5期553-561,共9页
In previous publications, the author has proposed a model of the electron’s internal structure, wherein a positively-charged negative mass outer shell and a negatively-charged positive mass central core are proposed ... In previous publications, the author has proposed a model of the electron’s internal structure, wherein a positively-charged negative mass outer shell and a negatively-charged positive mass central core are proposed to resolve the electron’s charge and mass inconsistencies. That model is modified in this document by assuming the electron’s radius is exactly equal to the classical electron radius. The attributes of the internal components of the electron’s structure have been recalculated accordingly. The shape of the electron is also predicted, and found to be slightly aspherical on the order of an oblate ellipsoid. This shape is attributed to centrifugal force and compliant outer shell material. It is interesting to note that all of the electron’s attributes, both external and internal, with the exception of mass and angular moment, are functions of the fine structure constant a, and can be calculated from just three additional constants: electron mass, Planck’s constant, and speed of light. In particular, the ratios of the outer shell charge and mass to the electron charge and mass, respectively, are 3/2a. The ratios of the central core charge and mass to the electron charge and mass, respectively, are 1-(3/2a). Attributes of the electron are compared with those of the muon. Charge and spin angular momentum are the same, while mass, magnetic moment, and radius appear to be related by the fine structure constant. The mass of the electron outer shell is nearly equal to the mass of the muon. The muon internal structure can be modeled exactly the same as for the electron, with exactly the same attribute relationships. 展开更多
关键词 Fine Structure Constant negative mass Electron Shape Electron Structure Electron mass Inconsistency Electron Charge Inconsistency MUON
下载PDF
A New Interpretation of the Higgs Vacuum Potential Energy Based on a Planckion Composite Model for the Higgs
6
作者 Christopher Pilot 《Journal of High Energy Physics, Gravitation and Cosmology》 2023年第3期666-683,共18页
We present a new interpretation of the Higgs field as a composite particle made up of a positive, with, a negative mass Planck particle. According to the Winterberg hypothesis, space, i.e., the vacuum, consists of bot... We present a new interpretation of the Higgs field as a composite particle made up of a positive, with, a negative mass Planck particle. According to the Winterberg hypothesis, space, i.e., the vacuum, consists of both positive and negative physical massive particles, which he called planckions, interacting through strong superfluid forces. In our composite model for the Higgs boson, there is an intrinsic length scale associated with the vacuum, different from the one introduced by Winterberg, where, when the vacuum is in a perfectly balanced state, the number density of positive Planck particles equals the number density of negative Planck particles. Due to the mass compensating effect, the vacuum thus appears massless, chargeless, without pressure, energy density, or entropy. However, a situation can arise where there is an effective mass density imbalance due to the two species of Planck particle not matching in terms of populations, within their respective excited energy states. This does not require the physical addition or removal of either positive or negative Planck particles, within a given region of space, as originally thought. Ordinary matter, dark matter, and dark energy can thus be given a new interpretation as residual vacuum energies within the context of a greater vacuum, where the populations of the positive and negative energy states exactly balance. In the present epoch, it is estimated that the dark energy number density imbalance amounts to, , per cubic meter, when cosmic distance scales in excess of, 100 Mpc, are considered. Compared to a strictly balanced vacuum, where we estimate that the positive, and the negative Planck number density, is of the order, 7.85E54 particles per cubic meter, the above is a very small perturbation. This slight imbalance, we argue, would dramatically alleviate, if not altogether eliminate, the long standing cosmological constant problem. 展开更多
关键词 Winterberg Model Planck Particles Positive and negative mass Planck Particles Planckions Quantum Vacuum Space as a Superfluid/Supersolid Extended Models for Space Cosmological Constant Higgs Field as a Composite Particle Higgs Boson Inherent Length Scale for the Vacuum Dark Energy
下载PDF
Gravity as a Unified Force
7
作者 Mark Ridler 《Journal of High Energy Physics, Gravitation and Cosmology》 2023年第4期1217-1236,共20页
A model universe is hypothesized where gravity is developed to take on the qualities of electrostatics. This necessarily breaks the Einstein Equivalence Principle where gravitational and inertial mass may vary. We are... A model universe is hypothesized where gravity is developed to take on the qualities of electrostatics. This necessarily breaks the Einstein Equivalence Principle where gravitational and inertial mass may vary. We are told that gravity and electromagnetism were unified in the earliest moments of the universe. Perhaps they are still unified today and the EEP is broken at the small scale. This paper shows a possible way how. For simplicity Newtonian Mechanics [1] are used throughout which means that formulae are only valid in the low mass, low speed limit. For high mass or high speed please refer to General Relativity [2]. Gravity is developed in the following sections: 1) Model A is attractive;standard physics. 2) Model AB is attractive/repulsive;Hermann Bondi [3];3) Model ABCD is likes vs opposites;non-standard physics. Also discussed is a new way of looking at Electron-Positron annihilation. 展开更多
关键词 negative mass Gravitational mass Inertial mass
下载PDF
On the Cosmic Evolution of the Quantum Vacuum Using Two Variable G Models and Winterberg’s Thesis
8
作者 Christopher Pilot 《Journal of High Energy Physics, Gravitation and Cosmology》 2023年第4期1134-1160,共27页
We work within a Winterberg framework where space, i.e., the vacuum, consists of a two component superfluid/super-solid made up of a vast assembly (sea) of positive and negative mass Planck particles, called planckion... We work within a Winterberg framework where space, i.e., the vacuum, consists of a two component superfluid/super-solid made up of a vast assembly (sea) of positive and negative mass Planck particles, called planckions. These material particles interact indirectly, and have very strong restoring forces keeping them a finite distance apart from each other within their respective species. Because of their mass compensating effect, the vacuum appears massless, charge-less, without pressure, net energy density or entropy. In addition, we consider two varying G models, where G, is Newton’s constant, and G<sup>-1</sup>, increases with an increase in cosmological time. We argue that there are at least two competing models for the quantum vacuum within such a framework. The first follows a strict extension of Winterberg’s model. This leads to nonsensible results, if G increases, going back in cosmological time, as the length scale inherent in such a model will not scale properly. The second model introduces a different length scale, which does scale properly, but keeps the mass of the Planck particle as, ± the Planck mass. Moreover we establish a connection between ordinary matter, dark matter, and dark energy, where all three mass densities within the Friedman equation must be interpreted as residual vacuum energies, which only surface, once aggregate matter has formed, at relatively low CMB temperatures. The symmetry of the vacuum will be shown to be broken, because of the different scaling laws, beginning with the formation of elementary particles. Much like waves on an ocean where positive and negative planckion mass densities effectively cancel each other out and form a zero vacuum energy density/zero vacuum pressure surface, these positive mass densities are very small perturbations (anomalies) about the mean. This greatly alleviates, i.e., minimizes the cosmological constant problem, a long standing problem associated with the vacuum. 展开更多
关键词 Winterberg Model Planck Particles Positive and negative mass Planck Particles Planckions Quantum Vacuum Space as a Superfluid/Supersolid Extended Models for Space Cosmological Constant Higgs Field as a Composite Particle Higgs Boson Inherent Length Scale for the Vacuum Dark Energy Cosmological Scaling Behavior for the Quantum Vacuum Variable G Models Extended Gravity Newton’s Constant as an Order Parameter High Energy Behavior for the Vacuum
下载PDF
A new tunable elastic metamaterial structure for manipulating band gaps/wave propagation 被引量:1
9
作者 Zhenyu WANG Zhaoyang MA +1 位作者 Xingming GUO Dongsheng ZHANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2021年第11期1543-1554,共12页
A one-dimensional mechanical lattice system with local resonators is proposed as an elastic metamaterial model,which shows negative mass and negative modulus under specific frequency ranges.The proposed representative... A one-dimensional mechanical lattice system with local resonators is proposed as an elastic metamaterial model,which shows negative mass and negative modulus under specific frequency ranges.The proposed representative units,consisting of accurately arranged rigid components,can generate controllable translational resonance and achieve negative mass and negative modulus by adjusting the local structural parameters.A shape memory polymer is adopted as a spring component,whose Young’s modulus is obviously affected by temperature,and the proposed metamaterials’tunable ability is achieved by adjusting temperature.The effect of the shape memory polymer’s stiffness variation on the band gaps is investigated detailedly,and the special phenomenon of intersecting dispersion curves is discussed,which can be designed and controlled by adjusting temperature.The dispersion relationship of the continuum metamaterial model affected by temperature is obtained,which shows great tunable ability to manipulate wave propagation. 展开更多
关键词 tunable elastic metamaterial negative mass negative modulus
下载PDF
Elastic metamaterials with local resonances:an overview
10
作者 Xiaoming Zhou Xiaoning Liu Gengkai Hu 《Theoretical & Applied Mechanics Letters》 CAS 2012年第4期1-12,共12页
Metamaterials are artificial composite materials engineered to have properties that may not be found in nature. By exploring locally resonant effect of the building units, elastic metamaterials are able to possess neg... Metamaterials are artificial composite materials engineered to have properties that may not be found in nature. By exploring locally resonant effect of the building units, elastic metamaterials are able to possess negative values of effective mass, effective bulk or shear modulus. Mass-spring and continuum material versions of these elastic metamaterials are reported and the physical mechanisms of negative effective parameters are demonstrated. Applications of metamaterials to acoustic cloaking and superlensing are also discussed. 展开更多
关键词 METAMATERIALS negative mass negative modulus RESONANCE CLOAKING superlensing
下载PDF
A Formulation of Spin Dynamics Using Schrodinger Equation
11
作者 Vu B.Ho 《Journal of Modern Physics》 2019年第11期1374-1393,共20页
In quantum mechanics, there is a profound distinction between orbital angular momentum and spin angular momentum in which the former can be associated with the motion of a physical object in space but the latter canno... In quantum mechanics, there is a profound distinction between orbital angular momentum and spin angular momentum in which the former can be associated with the motion of a physical object in space but the latter cannot. The difference leads to a radical deviation in the formulation of their corresponding dynamics in which an orbital angular momentum can be described by using a coordinate system but a spin angular momentum cannot. In this work, we show that it is possible to treat spin angular momentum in the same manner as orbital angular momentum by formulating spin dynamics using Schr&ouml;dinger equation in an intrinsic coordinate system. As an illustration, we apply the formulation to the dynamics of a hydrogen atom and show that the intrinsic spin angular momentum of the electron can take half-integral values and, in particular, the intrinsic mass of the electron can take negative values. We also consider a further extension by generalising the formulation so that it can be used to describe other intrinsic dynamics that may associate with a quantum particle, for example, when a hydrogen atom radiates a photon, the photon associated with the electron may also possess an intrinsic dynamics that can be described by an intrinsic wave equation that has a similar form to that for the electron. 展开更多
关键词 Spin Angular Momentum Spin Dynamics Orbital Angular Momentum Schrodinger Equation Half-Integer Values Intrinsic Coordinate Systems negative mass
下载PDF
Negative ion mass spectrometry of antimony and selenium
12
作者 刘炳寰 《Chinese Science Bulletin》 SCIE EI CAS 1996年第9期790-790,共1页
Because of the relatively high electron affinity of antimony, it is possible to obtain itsnegative ions by thermal ionization although it is not so easy. By means of reducing thework function on the surface of filamen... Because of the relatively high electron affinity of antimony, it is possible to obtain itsnegative ions by thermal ionization although it is not so easy. By means of reducing thework function on the surface of filament and introducing a kind of positive ion into 展开更多
关键词 negative ion mass spectrometry of antimony and selenium
原文传递
Synthesis of Fullerene Hydrazine Derivatives
13
作者 Shen Shengwen Zhu Ling +2 位作者 Yang Dailing Zhang Xungao Sheng Rongsheng 《Wuhan University Journal of Natural Sciences》 CAS 1997年第4期107-110,共4页
C 60 /C 70 mixture reacts with hydrazine hydrate catalysed by tetrabutylammonium bromide (TBAB) in the presence of air to afford fullerene hydrazine derivatives C 60 (OH) n(NHNH 2) n and C 70 (OH) n(NHNH 2) n,whi... C 60 /C 70 mixture reacts with hydrazine hydrate catalysed by tetrabutylammonium bromide (TBAB) in the presence of air to afford fullerene hydrazine derivatives C 60 (OH) n(NHNH 2) n and C 70 (OH) n(NHNH 2) n,which are characterized by means of MS and FTIR.A possible reaction mechanism is discussed. 展开更多
关键词 fullerene fullerene hydrazine derivative negative ion mass spectra
下载PDF
Analysis of the linkage positions and isomers of monosaccharide units in oligosaccharides by negative secondary ion mass spectrometry in combination with the stereoselective reaction with substituted boronic acid
14
作者 YAN,Lin FANG,Yi-Wei Institute of Chemistry,Chinese Academy of Sciences,Beijing 100080 《Chinese Journal of Chemistry》 SCIE CAS CSCD 1993年第1期53-58,共8页
The negative secondary ion mass spectrometry,in combination with the stereoselective derivatizations with substituted boronic acid RB(OH)_2,was used in the analysis of fourteen oligosac- charides.The mass spectra of t... The negative secondary ion mass spectrometry,in combination with the stereoselective derivatizations with substituted boronic acid RB(OH)_2,was used in the analysis of fourteen oligosac- charides.The mass spectra of the derivatives provide information on their linkage Positions and iso- merism of the individual monoscaccharide units.The results indicated that among the derivatives of the oligosaccharides analyzed,those with 1—4 and 1—6 linkages all presented the ion peaks at m/z 287,sometimes one more peak at m/z 449.Furthermore,a relationship was found between the linkage positions and the intensity orders of the derivative ions.Finally,the derivatives of the disaccharides with a galactose presented an intense ion peak at m/z 347,and those of oligosaccharides with 1—6 linkage to a galactose at terminal presented the ion at m/z 317.In the case of oligosaccharides with a fructose residue,characteristic ion of m/z 155 was produced.The conditions of stereoselective derivatizations and mass spectrometry were studied,in order to obtain a better reproducibility of the mass spectra. 展开更多
关键词 Analysis of the linkage positions and isomers of monosaccharide units in oligosaccharides by negative secondary ion mass spectrometry in combination with the stereoselective reaction with substituted boronic acid acid
全文增补中
Stereochemical effects in mass spectrometry——Ⅺ.Negative ion fast atom bombardment mass spectrometry of saccharides and glycosides using phenylboronic acid as reagent
15
作者 LI,Hong YANG,Hou-Jun CHEN,Shao-Nong CHEN,Yao-Zu Department of Chemistry,Lanzhou University,Lanzhou 730000 The author to whom correspondence should be addressed.Present address is Department of Chemistry,Tsinghua University,Beijing 100084 《Chinese Journal of Chemistry》 SCIE CAS CSCD 1992年第4期337-343,共0页
The negative ion fast atom bombardment (NIFAB) mass spectra of mono-,di-saccharides and glycosides using phenylboronic acid (PBA) as reagent have been studied.In the ion source,PBA reacts stereospecifically with the m... The negative ion fast atom bombardment (NIFAB) mass spectra of mono-,di-saccharides and glycosides using phenylboronic acid (PBA) as reagent have been studied.In the ion source,PBA reacts stereospecifically with the molecules containing cis-vicinal glycols to form characteristic ions, from which the stereo-isomers of saccharides can be definitely distinguished.Disaccharides and glyco- sides with β-glycosidic linkage seem to be unfavorabale to react with PBA,therefore,by comparison of the abundances of the characteristic ions,the configuration of the glycosidic linkage in these compounds may be inferred. 展开更多
关键词 FAB Stereochemical effects in mass spectrometry negative ion fast atom bombardment mass spectrometry of saccharides and glycosides using phenylboronic acid as reagent acid
全文增补中
Design of double negativity elastic metamaterial 被引量:2
16
作者 Y.C.Su C.T.Sun 《International Journal of Smart and Nano Materials》 SCIE EI 2015年第1期61-72,共12页
A metamaterial model that possesses simultaneously negative effective mass density and negative effective Young’s modulus is proposed in this study.Dispersion curves and dynamic responses of the model are investigate... A metamaterial model that possesses simultaneously negative effective mass density and negative effective Young’s modulus is proposed in this study.Dispersion curves and dynamic responses of the model are investigated.In the double negative frequency region,it is demonstrated that the phase velocity is negative.In addition,it was found that the band gap region of the metamaterial can be predicted accurately by taking parts of single-unit cell to analyze the steady-state response.The design is also fabricated by a 3D printer. 展开更多
关键词 acoustic metamaterial double negativity local resonance negative mass negative modulus
原文传递
Superluminal X-waves in a polariton quantum fluid
17
作者 Antonio Gianfrate Lorenzo Dominici +6 位作者 Oksana Voronych Michał Matuszewski Magdalena Stobińska Dario Ballarini Milena De Giorgi Giuseppe Gigli Daniele Sanvitto 《Light(Science & Applications)》 SCIE EI CAS CSCD 2017年第1期311-319,共9页
In this work,we experimentally demonstrate for the first time the spontaneous generation of two-dimensional exciton-polariton X-waves.X-waves belong to the family of localized packets that can sustain their shape with... In this work,we experimentally demonstrate for the first time the spontaneous generation of two-dimensional exciton-polariton X-waves.X-waves belong to the family of localized packets that can sustain their shape without spreading,even in the linear regime.This allows the wavepacket to maintain its shape and size for very low densities and very long times compared to soliton waves,which always necessitate a nonlinearity to compensate the diffusion.Here,we exploit the polariton nonlinearity and uniquely structured dispersion,comprising both positive-and negative-mass curvatures,to trigger an asymmetric four-wave mixing in momentum space.This ultimately enables the self-formation of a spatial X-wave front.Using ultrafast imaging experiments,we observe the early reshaping of the initial Gaussian packet into the X-pulse and its propagation,even for vanishingly small densities.This allows us to outline the crucial effects and parameters that drive the phenomena and to tune the degree of superluminal propagation,which we found to be in close agreement with numerical simulations. 展开更多
关键词 negative mass NONLINEARITY POLARITONS SUPERLUMINAL X-waves
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部