Imperial College London

DrVincenzoGiannini

Faculty of Natural SciencesDepartment of Physics

Academic Visitor
 
 
 
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Contact

 

+44 (0)20 7594 1588v.giannini Website

 
 
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Location

 

811Blackett LaboratorySouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
to

138 results found

Palmer SJ, Giannini V, 2021, Berry bands and pseudo-spin of topological photonic phases, Physical Review Research, Vol: 3

Journal article

Guerrini L, Garcia-Rico E, O'Loghlen A, Giannini V, Alvarez-Puebla RAet al., 2021, Surface-Enhanced Raman Scattering (SERS) Spectroscopy for Sensing and Characterization of Exosomes in Cancer Diagnosis, CANCERS, Vol: 13

Journal article

Palmer SJ, Giannini V, 2021, Berry bands and pseudo-spin of topological photonic phases, Physical Review Research, Vol: 3, ISSN: 2643-1564

Realising photonic analogues of the robust, unidirectional edge states ofelectronic topological insulators would improve our control of light on thenanoscale and revolutionise the performance of photonic devices. Here we showthat new symmetry protected topological phases can be detected by reformulatingenergy eigenproblems as Berry curvature eigenproblems. The "Berry bands" spanthe same eigenspace as the original valence energy bands, but separate intopseudo-spinful and pseudo-spinless subspaces in$\mathrm{C}_2\mathcal{T}$-symmetric crystals. We demonstrate the method on thewell-known case of Wu & Hu [Phys. Rev. Lett. 114, 223901 (2015)] and a recentlydiscovered fragilely topological crystal, and show that both crystals belong tothe same $\mathrm{C}_2\mathcal{T}$-protected $\mathbb{Z}_2$ topological phase.This work helps unite theory and numerics, and is useful in defining andidentifying new symmetry-protected phases in photonics and electronics.

Journal article

Alhammadi A, Lu J-Y, Almheiri M, Alzaabi F, Matouk Z, Al Teneiji M, Abu Al-Rub RK, Giannini V, Lee D-Wet al., 2021, Numerical Modelling and Optimization of Two-Dimensional Phononic Band Gaps in Elastic Metamaterials with Square Inclusions, APPLIED SCIENCES-BASEL, Vol: 11

Journal article

Xiao X, Maier SA, Giannini V, 2021, Ultrabroad-Band Direct Digital Refractive Index Imaging Based on Suspended Graphene Plasmon Nanocavities, ACS APPLIED NANO MATERIALS, Vol: 4, Pages: 1635-1642, ISSN: 2574-0970

Journal article

Geng D, Abdelwahab I, Xiao X, Cernescu A, Fu W, Giannini V, Maier SA, Li L, Hu W, Loh KP, Yang HYet al., 2021, One-Pot Confined Epitaxial Growth of 2D Heterostructure Arrays, ACS MATERIALS LETTERS, Vol: 3, Pages: 217-223

Journal article

Zhan Y, Zhang L, Rahmani M, Giannini V, Miroshnichenko AE, Hong M, Li X, Maier SA, Lei Det al., 2021, Synthetic Plasmonic Nanocircuits and the Evolution of Their Correlated Spatial Arrangement and Resonance Spectrum, ACS PHOTONICS, Vol: 8, Pages: 166-174, ISSN: 2330-4022

Journal article

Li K, Fitzgerald JM, Xiao X, Caldwell JD, Zhang C, Maier SA, Li X, Giannini Vet al., 2020, Graphene Plasmon Cavities Made with Silicon Carbide (vol 2, pg 3640, 2017), ACS OMEGA, Vol: 5, Pages: 30746-30746, ISSN: 2470-1343

Journal article

Tanaka YY, Albella P, Rahmani M, Giannini V, Maier SA, Shimura Tet al., 2020, Plasmonic linear nanomotor using lateral optical forces, SCIENCE ADVANCES, Vol: 6, ISSN: 2375-2548

Journal article

Palmer S, Giannini V, 2020, Peacock.jl: Photonic crystals in Julia, Journal of Open Source Software, Vol: 5, Pages: 2678-2678

Journal article

Feng Y, Leiderer P, Zhao R, Xiao X, Giannini V, Maier SA, Nemitz CA, Lin Z, Ding N, Kang G, Cheng D, Schmidt-Mende L, Huang L, Wang Yet al., 2020, Giant polarization anisotropic optical response from anodic aluminum oxide templates embedded with plasmonic metamaterials, OPTICS EXPRESS, Vol: 28, Pages: 29513-29528, ISSN: 1094-4087

Journal article

Proctor M, Xiao X, Craster RV, Maier SA, Giannini V, Arroyo Huidobro Pet al., 2020, Near- and far-field excitation of topological plasmonic metasurfaces, Photonics, Vol: 7, ISSN: 2304-6732

The breathing honeycomb lattice hosts a topologically non-trivial bulk phase due to the crystalline-symmetry of the system. Pseudospin-dependent edge states, which emerge at the interface between trivial and non-trivial regions, can be used for the directional propagation of energy. Using the plasmonic metasurface as an example system, we probe these states in the near- and far-field using a semi-analytical model. We provide the conditions under which directionality was observed and show that it is source position dependent. By probing with circularly-polarised magnetic dipoles out of the plane, we first characterise modes along the interface in terms of the enhancement of source emissions due to the metasurface. We then excite from the far-field with non-zero orbital angular momentum beams. The position-dependent directionality holds true for all classical wave systems with a breathing honeycomb lattice. Our results show that a metasurfac,e in combination with a chiral two-dimensional material, could be used to guide light effectively on the nanoscale.

Journal article

Francescato Y, Pocock SR, Giannini V, 2020, On the Non-Local Surface Plasmons' Contribution to the Casimir Force between Graphene Sheets, PHYSICS, Vol: 2, Pages: 22-31

Journal article

Blanco-Formoso M, Sousa-Castillo A, Xiao X, Marino-Lopez A, Turino M, Pazos-Perez N, Giannini V, Correa-Duarte MA, Alvarez-Puebla RAet al., 2019, Boosting the analytical properties of gold nanostars by single particle confinement into yolk porous silica shells, NANOSCALE, Vol: 11, Pages: 21872-21879, ISSN: 2040-3364

Journal article

Proctor M, Craster RV, Maier SA, Giannini V, Huidobro PAet al., 2019, Exciting pseudospin-dependent edge states in plasmonic metasurfaces, ACS Photonics, Vol: 6, Pages: 2985-2995, ISSN: 2330-4022

We study a plasmonic metasurface that supports pseudospin-dependent edge states confined at a subwavelength scale, considering full electrodynamic interactions including retardation and radiative effects. The spatial symmetry of the lattice of plasmonic nanoparticles gives rise to edge states with properties reminiscent of the quantum spin Hall effect in topological insulators. However, unlike the spin-momentum locking characteristic of topological insulators, these modes are not purely unidirectional and their propagation properties can be understood by analyzing the spin angular momentum of the electromagnetic field, which is inhomogeneous in the plane of the lattice. The local sign of the spin angular momentum determines the propagation direction of the mode under a near-field excitation source. We also study the optical response under far-field excitation and discuss in detail the effects of radiation and retardation.

Journal article

Fuentes-Edfuf Y, Sánchez-Gil JA, Garcia-Pardo M, Serna R, Tsibidis GD, Giannini V, Solis J, Siegel Jet al., 2019, Tuning the period of femtosecond laser induced surface structures in steel: From angled incidence to quill writing, Applied Surface Science, Vol: 493, Pages: 948-955, ISSN: 0169-4332

Exposure of metal surfaces to multiple ultrashort laser pulses under certain conditions leads to the formation of well-defined periodic surface structures. We show how the period of such structures in steel can be tuned over a wide range by controlling the complex interaction mechanisms triggered in the material. Amongst the different irradiation parameters that influence the properties of the induced structures, the angle of incidence of the laser beam occupies a prominent role. We present an experimental and theoretical investigation of this angle dependence in steel upon irradiation with laser pulses of 120 fs duration and 800 nm wavelength, while moving the sample at constant speed. Our findings can be grouped into two blocks. First, we observe the spatial coexistence of two different ripple periods at the steel surface, both featuring inverse scaling upon angle increase, which are related to forward and backward propagation of surface plasmon polaritons. To understand the underlying physical phenomena, we extend a recently developed model that takes into account quantitative properties of the surface roughness to the case of absorbing metals (large imaginary part of the dielectric function), and obtain an excellent match with the experimentally observed angle dependence. As second important finding, we observe a quill writing effect, also termed non-reciprocal writing, in form of a significant change of the ripple period upon reversing the sample movement direction. This remarkable phenomenon has been observed so far only inside dielectric materials and our work underlines its importance also in laser surface processing. We attribute the origin of symmetry breaking to the non-symmetric micro- and nanoscale roughness induced upon static multiple pulse irradiation, leading to non-symmetric modification of the wavevector of the coupled surface plasmon polariton.

Journal article

Park S-G, Xiao X, Min J, Mun C, Jung HS, Giannini V, Weissleder R, Maier SA, Im H, Kim D-Het al., 2019, Self-Assembly of Nanoparticle-Spiked Pillar Arrays for Plasmonic Biosensing, ADVANCED FUNCTIONAL MATERIALS, Vol: 29, ISSN: 1616-301X

Journal article

Pocock S, Huidobro PA, Giannini V, 2019, Bulk-edge correspondence and long range hopping in the topological plasmonic chain, Nanophotonics, Vol: 8, Pages: 1337-1347, ISSN: 2192-8606

The existence of topologically protected edge modes is often cited as a highly desirable trait of topological insulators. However, these edge states are not always present. A realistic physical treatment of long-range hopping in a one-dimensional dipolar system can break the symmetry that protects the edge modes without affecting the bulk topological number, leading to a breakdown in bulk-edge correspondence (BEC). Hence, it is important to gain a better understanding of where and how this occurs, as well as how to measure it. Here we examine the behaviour of the bulk and edge modes in a dimerised chain of metallic nanoparticles and in a simpler non-Hermitian next-nearest-neighbour model to provide some insights into the phenomena of bulk-edge breakdown. We construct BEC phase diagrams for the simpler case and use these ideas to devise a measure of symmetry-breaking for the plasmonic system based on its bulk properties. This provides a parameter regime in which BEC is preserved in the topological plasmonic chain, as well as a framework for assessing this phenomenon in other systems.

Journal article

Shautsova V, Gusken NA, Sidiropoulos T, Xiao X, Black NCG, Gilbertson AM, Giannini V, Maier SA, Cohen LF, Oulton RFet al., 2019, Plasmonic photo-thermo-electric effect in graphene, Conference on Lasers and Electro-Optics (CLEO), Publisher: IEEE, ISSN: 2160-8989

We present a novel photo-thermo-electric effect in graphene photo-detectors established by hot electrons concentration gradients at plasmonic contacts. Our description is crucial for an in depth understanding of graphene-based photo detection devices.

Conference paper

Levato T, Goncalves LV, Giannini V, 2019, Laser-plasma accelerated protons: energy increase in gas-mixtures usinghigh mass number atomic species, Publisher: arXiv

The idea of using a gas-mixture comprising atoms with high mass number inorder to increase proton energies in laser induced plasma acceleration at undercritical density is investigated by means of 2D PIC (Particle-In-Cell)simulations. Comparing and discussing the case of a pure hydrogen plasma, andthat of a plasma containing higher mass number species with a small percentageof hydrogen, we demonstrated that the mixture enhances the energies of theaccelerated protons. We also show that using a gas-mixture introduces thepossibility of using the densities ratio to change the relative acceleration ofthe species.

Working paper

Rider MS, Sokolikova M, Hanham SM, Navarro-Cia M, Haynes P, Lee D, Daniele M, Guidi MC, Mattevi C, Lupi S, Giannini Vet al., 2019, Experimental signature of a topological quantum dot, Publisher: arXiv

Topological insulators (TIs) present a neoteric class of materials, whichsupport delocalised, conducting surface states despite an insulating bulk. Dueto their intriguing electronic properties, their optical properties havereceived relatively less attention. Even less well studied is their behaviourin the nanoregime, with most studies thus far focusing on bulk samples - inpart due to the technical challenges of synthesizing TI nanostructures. Westudy topological insulator nanoparticles (TINPs), for which quantum effectsdominate the behaviour of the surface states and quantum confinement results ina discretized Dirac cone, whose energy levels can be tuned with thenanoparticle size. The presence of these discretized energy levels in turnleads to a new electron-mediated phonon-light coupling in the THz range. Wepresent the experimental realisation of Bi$_2$Te$_3$ TINPs and strong evidenceof this new quantum phenomenon, remarkably observed at room temperature. Thissystem can be considered a topological quantum dot, with applications to roomtemperature THz quantum optics and quantum information technologies.

Working paper

Palmer S, Xiao X, Pazos-Perez N, Guerrini L, Correa-Duarte M, Maier S, Craster R, Alvarez-Puebla R, Giannini Vet al., 2019, Extraordinarily transparent compact metallic metamaterials, Nature Communications, Vol: 10, ISSN: 2041-1723

The design of achromatic optical components requires materials with high transparency and low dispersion. We show that although metals are highly opaque, densely packed arrays of metallic nanoparticles can be more transparent to infrared radiation than dielectrics such as germanium, even when the arrays are over 75% metal by volume. Such arrays form effective dielectrics that are virtually dispersion-free over ultra-broadband ranges of wavelengths from microns up to millimeters or more. Furthermore, the local refractive indices may be tuned by altering the size, shape, and spacing of the nanoparticles, allowing the design of gradient-index lenses that guide and focus light on the microscale. The electric field is also strongly concentrated in the gaps between the metallic nanoparticles, and the simultaneous focusing and squeezing of the electric field produces strong ‘doubly-enhanced’ hotspots which could boost measurements made using infrared spectroscopy and other non-linear processes over a broad range of frequencies.

Journal article

Fuentes-Edfuf Y, Sanchez-Gil JA, Florian C, Giannini V, Solis J, Siegel Jet al., 2019, Surface plasmon polaritons on rough metal surfaces: role in the formation of laser-induced periodic surface structures, ACS Omega, Vol: 4, Pages: 6939-6946, ISSN: 2470-1343

The formation of self-organized laser-induced periodic surface structures (LIPSS) in metals, semiconductors, and dielectrics upon pulsed laser irradiation is a well-known phenomenon, receiving increased attention because of their huge technological potential. For the case of metals, a major role in this process is played by surface plasmon polaritons (SPPs) propagating at the interface of the metal with the medium of incidence. Yet, simple and advanced models based on SPP propagation sometimes fail to explain experimental results, even of basic features such as the LIPSS period. We experimentally demonstrate, for the particular case of LIPSS on Cu, that significant deviations of the structure period from the predictions of the simple plasmonic model are observed, which are very pronounced for elevated angles of laser incidence. In order to explain this deviation, we introduce a model based on the propagation of SPPs on a rough surface that takes into account the influence of the specific roughness properties on the SPP wave vector. Good agreement of the modeling results with the experimental data is observed, which highlights the potential of this model for the general understanding of LIPSS in other metals.

Journal article

Rider MS, Palmer SJ, Pocock SR, Xiao X, Huidobro PA, Giannini Vet al., 2019, A perspective on topological nanophotonics: current status and future challenges, Journal of Applied Physics, Vol: 125, ISSN: 0021-8979

Topological photonic systems, with their ability to host states protectedagainst disorder and perturbation, allow us to do with photons what topological insulators do with electrons. Topological photonics can refer to electronic systems coupled with light or purely photonic setups. By shrinking these systems to the nanoscale, we can harness the enhanced sensitivity observed in nanoscale structures and combine this with the protection of the topological photonic states, allowing us to design photonic local density of states and to push towards one of the ultimate goals of modern science: the precise control of photons at the nanoscale. This is paramount for both nano-technological applications and also for fundamental research in light matter problems. For purely photonic systems, we work with bosonic rather than fermionic states, so the implementation of topology in these systems requires new paradigms. Trying to face these challenges has helped in the creation of the exciting new field of topological nanophotonics, with far-reaching applications. In this prospective article we review milestones in topological photonics and discuss how they can be built upon at the nanoscale.

Journal article

Vo TNL, Xiao X, Jung HS, Giannini V, Maier SA, Kim D-H, Lee Y-I, Park S-Get al., 2019, Compact Integration of TiO2 Nanoparticles into the Cross-Points of 3D Vertically Stacked Ag Nanowires for Plasmon-Enhanced Photocatalysis, NANOMATERIALS, Vol: 9

Journal article

Fitzgerald JM, Giannini V, 2019, Surface phonon polaritonics made simple: great as plasmonics but lower losses, ADVANCED PHOTONICS, Vol: 1

Journal article

Wang N, Zeisberger M, Huebner U, Giannini V, Schmidt MAet al., 2019, Symmetry-breaking induced magnetic Fano resonances in densely packed arrays of symmetric nanotrimers, SCIENTIFIC REPORTS, Vol: 9, ISSN: 2045-2322

Journal article

Pazos-Perez N, Fitzgerald JM, Giannini V, Guerrini L, Alvarez-Puebla RAet al., 2019, Modular assembly of plasmonic core-satellite structures as highly brilliant SERS-encoded nanoparticles, NANOSCALE ADVANCES, Vol: 1, Pages: 122-131, ISSN: 2516-0230

Journal article

Zhang C, Cao G, Wu S, Shao W, Giannini V, Maier SA, Li Xet al., 2019, Thermodynamic loss mechanisms and strategies for efficient hot-electron photoconversion, NANO ENERGY, Vol: 55, Pages: 164-172, ISSN: 2211-2855

Journal article

Lauri A, Velleman L, Xiao X, Cortes E, Edel JB, Giannini V, Rakovich A, Maier SAet al., 2019, Collective modes of self-assembled supercluster metamaterials: towards label-free sensing, 4th International Conference on Applications of Optics and Photonics (AOP), Publisher: SPIE-INT SOC OPTICAL ENGINEERING, ISSN: 0277-786X

Conference paper

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