Plasmon Drag Research Articles

Photoinduced electric effects in various plasmonic materials

Photoinduced voltages associated with surface plasmon polariton excitations are studied both theoretically and experimentally in various plasmonic systems as the function of material, wavelength, and type of structure. Experimental photovoltage normalized to the absorbed power shows a general decrease upon an increase in the wavelength, enhancement in the nanostructured samples, and a strong variation in the magnitude as a function of the material, which are not in line with the theoretical predictions of the simple plasmonic pressure approach. The results can be used for clarification of the mechanisms and further development of an adequate theoretical approach to the plasmon drag effect.

Controlling optical properties and drag of photon and surface plasmon polaritons in triple quantum dot molecules and dots-metal plasmonic interface via tunneling-assisted quantum coherence

Optical properties of surface plasmon polaritons (SPPs) and drag of photon and SPPs attracted great attention owing to multi-fold potential fundamental and technological implications. In this paper, we investigate the nature of light propagation, optical properties of probe field and SPPs and drag of photon and SPPs in a four-level triple quantum dot molecule (TQDM) well and a dots-metallic plasmonic interface (DMPI). The quantum coherence in TQDM and coupled DMPI interface is achieved via interbands tunneling-assisted quantum coherence namely- classical electromagnetically induced transparency (EIT) and plasmonic induced transparency (PIT). In contrast to earlier studies, herein we employed Drude-model type dielectric constant of metal with inclusion of size-dependent correction term to account for the reduced electron relaxation rate near the thin metal interface. In particular, after solving the master density-matrix equation of the quantum dot system for the eigenvalues, we interpreted the calculated theoretical results on light dragging and optical properties of probe field and SPPs via tunneling-assisted dressed-state picture of EIT/PIT in the proposed TQDM system and DMPI interface. The tunneling parameter considerably tuned the nature of light propagation from subluminal to superluminal and vice versa, optical properties and drag of photon and SPPs. The maximum positive (negative) value of the group index for photon is of order 3.68×106 (2.685×106) while for SPPs it is of order 3×105. The maximum value of lateral drag for photon and SPPs is ±5×10-2m and ±1.173×10-3m, respectively. The calculated propagation length and wavelength for SPPs are 6.25×10-7m and 3.78×10-7 m which correspond to the quality factor of 10.38.

Optoelectronic Readout of STT-RAM Based on Plasmon Drag Effect

An opto-electronic readout of the memory state in spin transfer torque random access memory (STT-RAM) cells is proposed. A single optical beam illuminating an array of STT-RAM cells creates electrical potential along each STT-RAM cell due to optical rectification that can be further enhanced through plasmon drag effect (PLDE). Then, the photo-induced voltage is assumed to be measured by conventional electronics. Here, a theoretical modeling is performed, where the results provide an estimate of the photo-induced voltage in each memory cell and its variation with respect to the changes in state of the memory cell (parallel vs anti-parallel). Our study shows that the plasmonic enhancement facilitates ${\sim }$ 20 times enhancement in the voltage change due to state change of the each memory cell, compared to the case of out-of-resonance excitation. This enhancement potentially improves the memory readout rate if a proper supporting electronic circuit is available.

Complex conductivity dependent surface plasmon polaritons at the interface of metal and silver silica nanocomposites

AbstractSurface plasmon polariton (SPPs) is investigated with complex conductivity at the interface of metal and silver silica nonacomposites. The amplitude and phase of complex conductivity significantly influence the SPPs propagation. The value of Re(ksp) varies with the phase and norm of complex conductivity. Similarly the wavelength, propagation length, group velocity, decay time, penetration depth and rotary Plasmon drag of SPPs are investigated. These results may have vital applications in the field of wave‐guides, Plasmonster, data storage, chemical and biosensors.

Magnetically dependent plasmon drag in permalloy structures

Significant photovoltages are observed in permalloy grating-like structures in response to pulsed laser light illumination. Electrical signals are enhanced at plasmon resonance conditions and show a clear dependence on the magnetic field with a characteristic hysteresis. Estimations show that the effect could not be explained solely by laser-induced heating. Alternative mechanisms are discussed.

Coulomb drag in metal monochalcogenides double-layer structures with Mexican-hat band dispersions

We theoretically study the Coulomb drag resistivity and plasmon modes behavior for a system composed of two parallel p-type doped GaS monolayers with Mexican-hat valence energy band using the Boltzmann transport theory formalism. We investigate the effect of temperature, T, carrier density, p, and layer separation, d, on the plasmon modes and drag resistivity within the energy-independent scattering time approximation. Our results show that the density dependence of plasmon modes can be approximated by p 0.5. Also, the calculations suggest a d 0.2 and a d 0.1 dependencies for the acoustic and optical plasmon energies, respectively. Interestingly, we obtain that the behavior of drag resistivity in the double-layer metal monochalcogenides swings between the behavior of a double-quantum well system with parabolic dispersion and that of a double-quantum wire structure with a large carrier density of states. In particular, the transresistivity value reduces exponentially with increasing the distance between layers. Furthermore, the drag resistivity changes as T 2/p 4 (T 2.8/p 4.5) at low (intermediate) temperatures. Finally, we compare the drag resistivity as a function of temperature for GaS with other Mexican-hat materials including GaSe and InSe and find that it adopts higher values when the metal monochalcogenide has smaller Mexican-hat height.

Extreme sensitivity of plasmon drag to surface modification

Giant enhancement of photocurrents in plasmonic structures (plasmon drag effect) provides opportunities for compact electric monitoring of plasmonic effects, and thus is promising for plasmonic-based sensing applications. In the experiment, we measure photoinduced electric signals in flat and profile-modulated systems, and test their sensitivity to small changes of the local dielectric environment, such as a presence of Langmuir–Blodgett monolayers at the metal surface. We show that the addition of a stearic acid monolayer leading to a small shift in plasmon resonance conditions can be ultimately resolved with electrical measurements as the switching in the photovoltage polarity.

Plasmon drag effect with sharp polarity switching

The generation of significant photocurrents observed in plasmonic metasurfaces is interesting from a fundamental point of view and promising for applications in plasmon-based electronics and plasmonic sensors with compact electrical detection. We show that photoinduced voltages in strongly modulated plasmonic surfaces demonstrate a highly asymmetric angular dependence with polarity switching around the plasmon resonance conditions. The effects are tentatively attributed to coupling between localized and propagating plasmons.

Plasmon ratchet effect with electrons and holes simultaneously existing in the graphene channel: a promising effect for the terahertz detection

In this work, the plasmon drag effect in the grating gated graphene with symmetric unit cell, the plasmon ratchet effect and the photo-thermoelectric effect in the grating gated graphene with asymmetric unit cell are studied. The correlation between the total responsivity of the plasmon drag effect and the source-drain bias is calculated numerically through the hydrodynamic approach under small source-drain bias approximation. The total responsivity of the plasmon drag effect under small source-drain bias is found to be much smaller than the responsivity of the unidirectional travelling plasmons. The responsivity of the plasmon ratchet effect is calculated by fixing the lengths of the longer gated region and ungated region and changing the lengths of the shorter gated region and ungated region. The results show that non-zero plasmon ratchet responsivity can be obtained by only assuming one kind of charge carrier in the whole channel. By assuming holes in the shorter gated region and electrons in the other regions, the maximum responsivity is much higher than the former and can be as high as that reported in the reference. The responsivity of the photo-thermoelectric effect can be higher than that of the plasmon ratchet effect for currently available graphene. For ideal graphene with ultrahigh mobility, however, the responsivity of the photo-thermoelectric effect is orders of magnitude smaller than that of the plasmon ratchet effect.

Plasmonic pressure in profile-modulated and rough surfaces

The electromagnetic momentum loss approach is applied to predict the plasmon drag effect in profile-modulated gold films at different amplitudes of surface modulations. Direct proportionality of energy and momentum transfer in interactions of plasmons and free electrons in metal is proven to be valid for surfaces with relatively low height modulation amplitudes. An equivalent circuit model is discussed, which can provide qualitative description of the plasmon-induced electrical effects in modulated surfaces and surfaces with random roughness.

Polarization-dependent plasmonic photocurrents in two-dimensional electron systems

Plasmonic polarization dependent photocurrents in a homogeneous two-dimensional electron system are studied. Those effects are completely different from the photon drag and electronic photogalvanic effects as well as from the plasmonic ratchet effect in a density modulated two-dimensional electron system. Linear and helicity-dependent contributions to the photocurrent are found. The linear contribution can be interpreted as caused by the longitudinal and transverse plasmon drag effect. The helicity-dependent contribution originates from the non-linear electron convection and changes its sign with reversing the plasmonic field helicity. It is shown that the helicity-dependent component of the photocurrent can exceed the linear one by several orders of magnitude in high-mobility two-dimensional electron systems. The results open possibilities for all-electronic detection of the radiation polarization states by exciting the plasmonic photocurrents in two-dimensional electron systems.

On the nature of the plasmon drag effect

Light-matter momentum transfer in plasmonic materials is theoretically discussed in the framework of plasmonic pressure mechanism taking into account non-equilibrium electron dynamics and thermalization process. We show that our approach explains the experimentally observed relationship between the plasmon-related electromotive force and absorption and allows one to correctly predict the magnitude of the plasmon drag emf in flat metal films. We extend our theory to metal films with modulated profiles and show that the simple relationship between plasmonic energy and momentum transfer holds at relatively small amplitudes of height modulation and an approximation of laminar electron drift. Theoretical groundwork is laid for further investigations of shape-controlled plasmon drag in nanostructured metal.

Surface plasmon drag effect in a dielectrically modulated metallic thin film

We have experimentally and numerically investigated photo-induced voltage (PIV) effect across a Au film with a dielectric grating. We observed strongly enhanced voltage when surface plasmon polariton (SPP) is excited. It was found that electrons in the Au film are driven to the propagation direction of SPP. We have numerically shown that dissipative force called as scattering force well elucidates the experimental result for the first time. It is also clarified that this effect can be attributed to the momentum transfer from SPP to free carriers in the Au film. Thus the effect we observed can be called as surface plasmon drag effect in analogy with the photon drag effect.

Effect of finite temperature correlations on plasmon and coulomb drag in coupled quantum wells

We calculate the temperature dependence of correlations in coupled quantum wells using an STLS formalism generalized to finite temperatures. We investigate the effects of the temperature dependence of the correlations on the acoustic and optical plasmon dispersion curves and on Coulomb drag. Correlations are known to depress the energies of the two plasmons, while finite temperatures tend to increase the energies. We find this can result in considerable cancellation between the two effects at finite temperatures. We find that at temperatures k B T< E F, the local fields do not change appreciably with temperature so that in calculating the temperature dependence of the Coulomb drag using the zero temperature local fields suffices. The pair correlation function within the layers is also found to be insensitive to temperatures for k B T< E F. For higher temperatures than this the pair correlation function for small separations starts to increase as the exchange-correlation hole shrinks.