Imperial College London

Professor Ortwin Hess

Faculty of Natural SciencesDepartment of Physics

Leverhulme Chair in Metamaterials
 
 
 
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Contact

 

+44 (0)20 7594 7586o.hess Website

 
 
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Location

 

806Blackett LaboratorySouth Kensington Campus

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Summary

 

Publications

Publication Type
Year
to

400 results found

Bello F, Kongsuwan N, Donegan JF, Hess Oet al., 2020, Controlled Cavity-Free, Single-Photon Emission and Bipartite Entanglement of Near-Field-Excited Quantum Emitters, NANO LETTERS, Vol: 20, Pages: 5830-5836, ISSN: 1530-6984

Journal article

Kamp M, de Nijs B, Kongsuwan N, Saba M, Chikkaraddy R, Readman CA, Deacon WM, Griffiths J, Barrow SJ, Ojambati OS, Wright D, Huang J, Hess O, Scherman OA, Baumberg JJet al., 2020, Cascaded nanooptics to probe microsecond atomic-scale phenomena, PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, Vol: 117, Pages: 14819-14826, ISSN: 0027-8424

Journal article

Castellanos LR, Kahk JM, Hess O, Lischner Jet al., 2020, Generation of plasmonic hot carriers from d-bands in metallic nanoparticles, Journal of Chemical Physics, Vol: 152, ISSN: 0021-9606

We present an approach to master the well-known challenge of calculating the contribution of d-bands to plasmon-induced hot carrier rates in metallic nanoparticles. We generalize the widely used spherical well model for the nanoparticle wavefunctions to flat d-bands using the envelope function technique. Using Fermi’s golden rule, we calculate the generation rates of hot carriers after the decay of the plasmon due to transitions either from a d-band state to an sp-band state or from an sp-band state to another sp-band state. We apply this formalism to spherical silver nanoparticles with radii up to 20 nm and also study the dependence of hot carrier rates on the energy of the d-bands. We find that for nanoparticles with a radius less than 2.5 nm, sp-band state to sp-band state transitions dominate hot carrier production, while d-band state to sp-band state transitions give the largest contribution for larger nanoparticles.

Journal article

Saba M, Wong S, Elman M, Oh SS, Hess Oet al., 2020, Nature of topological protection in photonic spin and valley Hall insulators, PHYSICAL REVIEW B, Vol: 101, ISSN: 2469-9950

Journal article

Horton MJ, Ojambati OS, Chikkaraddy R, Deacon WM, Kongsuwan N, Demetriadou A, Hess O, Baumberg JJet al., 2020, Nanoscopy through a plasmonic nanolens, PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, Vol: 117, Pages: 2275-2281, ISSN: 0027-8424

Journal article

Kongsuwan N, Demetriadou A, Horton M, Chikkaraddy R, Baumberg JJ, Hess Oet al., 2020, Plasmonic Nanocavity Modes: From Near-Field to Far-Field Radiation, ACS PHOTONICS, Vol: 7, Pages: 463-471, ISSN: 2330-4022

Journal article

Wong S, Saba M, Hess O, Oh SSet al., 2020, Gapless unidirectional photonic transport using all-dielectric kagome lattices, Physical Review Research, Vol: 2

Journal article

Crai A, Demetriadou A, Hess O, 2020, Electron Beam Interrogation and Control of Ultrafast Plexcitonic Dynamics, ACS Photonics, ISSN: 2330-4022

Journal article

Liu X, Kongsuwan N, Li X, Zhao D, Wu Z, Hess O, Zhang Xet al., 2019, Tailoring the Third-Order Nonlinear Optical Property of a Hybrid Semiconductor Quantum Dot-Metal Nanoparticle: From Saturable to Fano-Enhanced Absorption, JOURNAL OF PHYSICAL CHEMISTRY LETTERS, Vol: 10, Pages: 7594-7602, ISSN: 1948-7185

Journal article

Kongsuwan N, Xiong X, Bai P, You J-B, Png CE, Wu L, Hess Oet al., 2019, Quantum plasmonic immunoassay sensing, Nano Letters: a journal dedicated to nanoscience and nanotechnology, Vol: 19, Pages: 5853-5861, ISSN: 1530-6984

Plasmon–polaritons are among the most promising candidates for next-generation optical sensors due to their ability to support extremely confined electromagnetic fields and empower strong coupling of light and matter. Here we propose quantum plasmonic immunoassay sensing as an innovative scheme, which embeds immunoassay sensing with recently demonstrated room-temperature strong coupling in nanoplasmonic cavities. In our protocol, the antibody–antigen–antibody complex is chemically linked with a quantum emitter label. Placing the quantum-emitter-enhanced antibody–antigen–antibody complexes inside or close to a nanoplasmonic (hemisphere dimer) cavity facilitates strong coupling between the plasmon–polaritons and the emitter label resulting in signature Rabi splitting. Through rigorous statistical analysis of multiple analytes randomly distributed on the substrate in extensive realistic computational experiments, we demonstrate a drastic enhancement of the sensitivity up to nearly 1500% compared to conventional shifting-type plasmonic sensors. Most importantly and in stark contrast to classical sensing, we achieve in the strong-coupling (quantum) sensing regime an enhanced sensitivity that is no longer dependent on the concentration of antibody–antigen–antibody complexes down to the single-analyte limit. The quantum plasmonic immunoassay scheme thus not only leads to the development of plasmonic biosensing for single molecules but also opens up new pathways toward room-temperature quantum sensing enabled by biomolecular inspired protocols linked with quantum nanoplasmonics.

Journal article

Wong S, Saba M, Hess O, Oh SSet al., 2019, Photonic topological insulator edge modes using all-dielectric kagome photonic crystals, Pages: X471-X473

© 2019 IEEE. Photonic topological insulators are promising photonic structures which can exhibit unidirectional propagation of edge states insensitive to bendings, fabrication imperfections or temperature variations. Recently, an all-dielectric perturbed honeycomb topological photonic crystal has attracted attention due to its simplicity of fabrication. However, its edge states intrinsically suffer from back-reflection due to the symmetry breaking at the interface. Here, we propose an all-dielectric reciprocal photonic topological insulator based on the geometry of a kagome lattice in which the topological edge modes do not undergo back-reflection for termination along the $\Gamma - K$ direction. In contrast to the perturbed honeycomb, the edge modes in our kagome-based structure are below the light cone leading to improved vertical mode confinement.

Conference paper

Bello F, Sanvito S, Hess O, Donegan JFet al., 2019, Shaping and Storing Magnetic Data Using Pulsed Plasmonic Nanoheating and Spin-Transfer Torque, ACS PHOTONICS, Vol: 6, Pages: 1524-1532, ISSN: 2330-4022

Journal article

Roman Castellanos L, Hess O, Lischner J, 2019, Single plasmon hot carrier generation in metallic nanoparticles, Communications Physics, Vol: 2, ISSN: 2399-3650

Hot carriers produced from the decay of localized surface plasmons in metallic nanoparticles are intensely studied because of their optoelectronic, photovoltaic and photocatalytic applications. From a classical perspective, plasmons are coherent oscillations of the electrons in the nanoparticle, but their quantized nature comes to the fore in the novel field of quantum plasmonics. In this work, we introduce a quantum-mechanical material-specific approach for describing the decay of single quantized plasmons into hot electrons and holes. We find that hot carrier generation rates differ significantly from semiclassical predictions. We also investigate the decay of excitations without plasmonic character and show that their hot carrier rates are comparable to those from the decay of plasmonic excitations for small nanoparticles. Our study provides a rigorous and general foundation for further development of plasmonic hot carrier studies in the plasmonic regime required for the design of ultrasmall devices.

Journal article

Dolan JA, Dehmel R, Demetriadou A, Gu Y, Wiesner U, Wilkinson TD, Gunkel I, Hess O, Baumberg JJ, Steiner U, Saba M, Wilts BDet al., 2019, Metasurfaces atop metamaterials: surface morphology induces linear dichroism in gyroid optical metamaterials, Advanced Materials, Vol: 31, ISSN: 0935-9648

Optical metamaterials offer the tantalizing possibility of creating extraordinary optical properties through the careful design and arrangement of subwavelength structural units. Gyroid-structured optical metamaterials possess a chiral, cubic, and triply periodic bulk morphology that exhibits a redshifted effective plasma frequency. They also exhibit a strong linear dichroism, the origin of which is not yet understood. Here, the interaction of light with gold gyroid optical metamaterials is studied and a strong correlation between the surface morphology and its linear dichroism is found. The termination of the gyroid surface breaks the cubic symmetry of the bulk lattice and gives rise to the observed wavelength- and polarization-dependent reflection. The results show that light couples into both localized and propagating plasmon modes associated with anisotropic surface protrusions and the gaps between such protrusions. The localized surface modes give rise to the anisotropic optical response, creating the linear dichroism. Simulated reflection spectra are highly sensitive to minute details of these surface terminations, down to the nanometer level, and can be understood with analogy to the optical properties of a 2D anisotropic metasurface atop a 3D isotropic metamaterial. This pronounced sensitivity to the subwavelength surface morphology has significant consequences for both the design and application of optical metamaterials.

Journal article

Trofimov A, Gric T, Hess O, 2019, Three-layered nanostructured metamaterials for surface plasmon polariton guiding, Journal of Mathematical Chemistry, Vol: 57, Pages: 190-201, ISSN: 0259-9791

© 2018, Springer Nature Switzerland AG. A novel metamaterial (MM) to guide surface plasmon polariton (SPP) is considered. Specific example of three-layered nanostructured MM and its dispersion engineering are studied in details allowing the development of new devices. Herein we deal with the general original concept of MMs based on inclusions of the additional layers as with a promising class of materials. The metal material stands for as the limiting factor of the frequency range that SPP mode exists. It is worthwhile noting that the SPP mode at high frequency is characterized by extremely large loss. The former restriction causes serious limitations for the potential applications of SPP in the field of optical interconnection, active SPP devices and so on. The surface mode guided by dielectric/graphene/dielectric multilayers MM has been studied based on the theory of electromagnetic field aiming to extend the frequency range of SPP mode. It is demonstrated that surface mode could be supported by the MM. Moreover, the frequency range to where conventional metal SPP cannot exist is extended. Herein, it is concluded that, the MM guided SPP mode can potentially be used to enhance the plasmonic performance over traditional metal one by varying the structure parameters.

Journal article

Gric T, Trofimov A, Hess O, 2019, Manipulating surface plasmon polaritons with nanostructured TCO metamaterials, JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS, Vol: 33, Pages: 493-503, ISSN: 0920-5071

Journal article

Gric T, Hess O, 2019, Slow and Stopped Light in Metamaterials, Phenomena of Optical Metamaterials, Publisher: Elsevier, Pages: 155-173, ISBN: 9780128138960

Book chapter

Gric T, Hess O, 2019, Metasurfaces, Phenomena of Optical Metamaterials, Publisher: Elsevier, Pages: 131-154, ISBN: 9780128138960

Book chapter

Gric T, Hess O, 2019, Types of Metamaterials, Phenomena of Optical Metamaterials, Publisher: Elsevier, Pages: 1-39, ISBN: 9780128138960

Book chapter

Gric T, Hess O, 2019, Metamaterial Cloaking, Phenomena of Optical Metamaterials, Publisher: Elsevier, Pages: 175-186, ISBN: 9780128138960

Book chapter

Gric T, Hess O, 2019, Active Optical Metamaterials, Phenomena of Optical Metamaterials, Publisher: Elsevier, Pages: 187-261, ISBN: 9780128138960

Book chapter

Gric T, Hess O, 2019, Surface Plasmon Polaritons at Metamaterial Interfaces, Phenomena of Optical Metamaterials, Publisher: Elsevier, Pages: 75-102, ISBN: 9780128138960

Book chapter

Gric T, Hess O, 2019, Electromagnetics of Metamaterials, Phenomena of Optical Metamaterials, Publisher: Elsevier, Pages: 41-73, ISBN: 9780128138960

Book chapter

Gric T, Hess O, 2019, Disorder in Metamaterials, Phenomena of Optical Metamaterials, Publisher: Elsevier, Pages: 103-130, ISBN: 9780128138960

Book chapter

Guazzotti S, Pusch A, Reiter DE, Hess Oet al., 2018, Dynamic theory of nanophotonic control of two-dimensional semiconductor nonlinearities, Physical Review B, Vol: 98, ISSN: 2469-9950

We introduce a Maxwell-Bloch simulation approach which self-consistently combines a microscopic description of the carrier and polarization dynamics of a transition-metal-dichalcogenide (TMDC) monolayer with a spatiotemporal full-wave time-domain simulation of Maxwell's equations on the basis of a finite-difference time-domain (FDTD) method beyond the slowly varying amplitude or paraxial approximations. This offers a platform to realistically model, in particular, the typical ultrafast optical excitation experiments in micro- and nanocavities. Our simulations confirm that the weak screening of the Coulomb interaction in TMDC monolayers yields pronounced exciton lines in the linear spectrum and we uncover the second-order nonlinearity represented in the semiconductor Maxwell-Bloch equations by an intraband dipole moment. This allows us to calculate the spectral shape of the exceptionally strong second-harmonic generation around the exciton lines of TMDC monolayers. We demonstrate that the second-harmonic signal can remarkably be further enhanced by several orders of magnitude through a suitably designed (one-dimensional) photonic microcavity. Due to its self-consistency, flexibility, explicit spatio-temporal resolution on the nanoscale and the ready access to light field and electron dynamics, our theory and computational approach is an ideal platform to design and explore spatiotemporal nonlinear and quantum dynamics in complex photonic or plasmonic micro- and nanostructures for optoelectronic, nanophotonic and quantum applications of TMDC monolayers.

Journal article

Kerber R, Fitzgerald J, Oh S, Reiter D, Hess Oet al., 2018, Orbital angular momentum dichroism in nanoantennas, Communications Physics, Vol: 1, ISSN: 2399-3650

When light interacts with matter, dichroism with respect to the handedness of circularly polarized light is well established. But what happens if the light further possesses an orbital angular momentum? In this paper, we discuss possible definitions of orbital angular momentum dichroism and define a new type of dichroism, the class dichroism. By numerically calculating the scattering cross-section spectra, we study the dichroism of a plasmonic nanostructure interacting with orbital angular momentum light. By considering the exemplary case of twisted, stacked nanorods, we show that the orbital angular momentum dichroism can be as strong as dichroism induced by circular polarization. We present a detailed classification of the different types of orbital angular momentum dichroism, which paves the way for new chiroptic spectroscopic techniques.

Journal article

Karwat P, Reiter D, Kuhn T, Hess Oet al., 2018, Coherent phonon lasing in a thermal quantum nanomachine, Physical Review A, Vol: 98, ISSN: 1050-2947

The notion of nanomachines has recently emerged to engage and use collective action of ensembles of nanoscale components or systems. Here we present a heat-gradient driven nanomachine concept which through appropriate coupling between quantum nanosystems is capable of realizing and maintaining an inversion. Based on a Lindblad form of the quantum master equation with a semiclassical coupling to the lattice displacement phonon field we show that this positive inversion can be harnessed to generate coherent optomechanical oscillations and phonon lasing.

Journal article

Crai A, Pusch A, Reiter D, Roman Castellanos L, Kuhn T, Hess Oet al., 2018, Coulomb effects on the photoexcited quantum dynamics of electrons in a plasmonic nanosphere, Physical review B: Condensed matter and materials physics, Vol: 98, ISSN: 1098-0121

With recent experiments investigating the optical properties of progressively smaller plasmonic particles, quantum effects become increasingly more relevant, requiring a microscopic description. Using the density matrix formalism we analyze the photoexcited few-electron dynamics of a small plasmonic nanosphere. Following the standard derivation of the bulk plasmon we particularly aim at elucidating the role of the Coulomb interaction. Calculating the dielectric susceptibility spectrum in the linear optical response we find discrete resonances resulting from a collective response mediated by the Coulomb interaction between the electrons. In the nonlinear regime, the occupations of the system exhibit oscillations between the interacting eigenstates. Our approach provides an ideal platform to study and explain nonlinear and quantum plasmonics, revealing that the photoexcited dynamics of plasmonic nanospheres has similarities with and combines characteristics of both the well-known two-level Rabi dynamics and the collective many-electron behavior typical of plasmons.

Journal article

Bittner S, Guazzotti S, Zeng Y, Hu X, Yilmaz H, Kim K, Oh SS, Wang QJ, Hess O, Cao Het al., 2018, Suppressing spatiotemporal lasing instabilities with wave-chaotic microcavities, Science, Vol: 361, Pages: 1225-1230, ISSN: 0036-8075

Spatiotemporal instabilities are widespread phenomena resulting from complexity and nonlinearity. In broad-area edge-emitting semiconductor lasers, the nonlinear interactions of multiple spatial modes with the active medium can result in filamentation and spatiotemporal chaos. These instabilities degrade the laser performance and are extremely challenging to control. We demonstrate a powerful approach to suppress spatiotemporal instabilities using wave-chaotic or disordered cavities. The interference of many propagating waves with random phases in such cavities disrupts the formation of self-organized structures such as filaments, resulting in stable lasing dynamics. Our method provides a general and robust scheme to prevent the formation and growth of nonlinear instabilities for a large variety of high-power lasers.

Journal article

Hess O, 2018, Strong coupling in nanoplasmonic cavities and metamaterials (Conference Presentation), Metamaterials, Metadevices, and Metasystems 2018, Publisher: SPIE

Conference paper

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