Negative Effective Mass in Plasmonic Systems

Mapping Intimacies ◽

10.20944/preprints202003.0418.v1 ◽

2020 ◽

Author(s):

Edward Bormashenko ◽

Irina Legchenkova

Keyword(s):

Effective Mass ◽

Plasma Frequency ◽

Electron Gas ◽

Metallic Particle ◽

Plasma Oscillations ◽

Mechanical Coupling ◽

Negative Effective Mass ◽

External Frequency ◽

Elastic Spring ◽

Ionic Lattice

We report the negative effective mass metamaterials based on the electro-mechanical coupling exploiting plasma oscillations of a free electron gas. The negative mass appears as a result of vibration of a metallic particle with a frequency of ω which is close the frequency of the plasma oscillations of the electron gas m_2 relatively to the ionic lattice m_1. The plasma oscillations are represented with the elastic spring k_2=ω_p^2 m_2, where ω_p is the plasma frequency. Thus, the metallic particle vibrated with the external frequency ω is described by the effective mass m_eff=m_1+(m_2 ω_p^2)/(ω_p^2-ω^2 ) , which is negative when the frequency ω approaches ω_p from above. The idea is exemplified with two conducting metals, namely Au and Li.

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Negative Effective Mass in Plasmonic Systems

Materials ◽

10.3390/ma13081890 ◽

2020 ◽

Vol 13 (8) ◽

pp. 1890 ◽

Cited By ~ 1

Author(s):

Edward Bormashenko ◽

Irina Legchenkova

Keyword(s):

Effective Mass ◽

Mass Density ◽

Electron Gas ◽

Metallic Particle ◽

Plasma Oscillations ◽

Mechanical Coupling ◽

Negative Effective Mass ◽

External Frequency ◽

Elastic Spring ◽

Ionic Lattice

We report the negative effective mass (density) metamaterials based on the electro-mechanical coupling exploiting plasma oscillations of a free electron gas. The negative mass appears as a result of the vibration of a metallic particle with a frequency of ω, which is close the frequency of the plasma oscillations of the electron gas m 2 relative to the ionic lattice m 1 . The plasma oscillations are represented with the elastic spring k 2 = ω p 2 m 2 , where ω p is the plasma frequency. Thus, the metallic particle vibrated with the external frequency ω is described by the effective mass m e f f = m 1 + m 2 ω p 2 ω p 2 − ω 2 , which is negative when the frequency ω approaches ω p from above. The idea is exemplified with two conducting metals, namely Au and Li.

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Negative Effective Mass in Plasmonic Systems II: Elucidating the Optical and Acoustical Branches of Vibrations and the Possibility of Anti-Resonance Propagation

Materials ◽

10.3390/ma13163512 ◽

2020 ◽

Vol 13 (16) ◽

pp. 3512

Author(s):

Edward Bormashenko ◽

Irina Legchenkova ◽

Mark Frenkel

Keyword(s):

Effective Mass ◽

Electron Gas ◽

Soda Lime ◽

Metallic Particle ◽

Soda Lime Glass ◽

Negative Mass ◽

Plasma Oscillations ◽

Mechanical Coupling ◽

Longitudinal Modes ◽

Negative Effective Mass

We report the negative effective mass metamaterials based on the electro-mechanical coupling exploiting plasma oscillations of free electron gas. The negative mass appears as a result of the vibration of a metallic particle with a frequency ω which is close to the frequency of the plasma oscillations of the electron gas m2, relative to the ionic lattice m1. The plasma oscillations are represented with the elastic spring constant k2=ωp2m2, where ωp is the plasma frequency. Thus, the metallic particle vibrating with the external frequency ω is described by the effective mass meff=m1+m2ωp2ωp2−ω2, which is negative when the frequency ω approaches ωp from above. The idea is exemplified with two conducting metals, namely Au and Li embedded in various matrices. We treated a one-dimensional lattice built from the metallic micro-elements meff connected by ideal springs with the elastic constant k1 representing various media such as polydimethylsiloxane and soda-lime glass. The optical and acoustical branches of longitudinal modes propagating through the lattice are elucidated for various ratios ω1ωp, where ω12=k1m1 and k1 represents the elastic properties of the medium. The 1D lattice, built from the thin metallic wires giving rise to low frequency plasmons, is treated. The possibility of the anti-resonant propagation, strengthening the effect of the negative mass occurring under ω = ωp = ω1, is addressed.

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