Publications (64)
The missing link between standing- and traveling-wave resonators
Qi Zhong, Haoqi Zhao, Liang Feng +3
Optical resonators are structures that utilize wave interference and feedback to confine light in all three dimensions. Depending on the feedback mechanism, resonators can support…
Quantum coherences of indistinguishable particles
Jan Sperling, Armando Perez-Leija, Kurt Busch +1
We study different notions of quantum correlations in multipartite systems of distinguishable and indistinguishable particles. Based on the definition of quantum coherence for a si…
Multiphoton Quantum-State Engineering using Conditional Measurements
Omar S. Magana-Loaiza, Roberto de J. Leon-Montiel, Armando Perez-Leija +7
The quantum theory of electromagnetic radiation predicts characteristic statistical fluctuations for light sources as diverse as sunlight, laser radiation and molecule fluorescence…
TE resonances in graphene-dielectric structures
Julia F. M. Werra, Francesco Intravaia, Kurt Busch
We investigate the dispersion relations of TE resonances in different graphene-dielectric structures. Previous work has shown that when a graphene layer is brought into contact wit…
Non-Hermitian topological filters
Vinzenz Zimmermann, Amin Hashemi, Kurt Busch +2
We introduce a non-Hermitian photonic filter that harnesses dissipation to selectively isolate a desired topological state. In science and engineering, dissipation is often used to…
Polaritonic Contribution to the Casimir Energy between two Graphene Layers
Christoph H. Egerland, Kurt Busch, Francesco Intravaia
We study the role of surface polaritons in the zero-temperature Casimir effect between two graphene layers that are described by the Dirac model. A parametric approach allows us to…
Extended hydrodynamic description for nonequilibrium atom-surface interactions
Daniel Reiche, Marty Oelschläger, Kurt Busch +1
The dissipative properties of spatially nonlocal conductors are investigated in the context of quantum friction acting on an atom moving above a macroscopic body. The focus is on a…
Modeling electromagnetic resonators using quasinormal modes
Philip Trøst Kristensen, Kathrin Herrmann, Francesco Intravaia +1
We present a bi-orthogonal approach for modeling the response of localized electromagnetic resonators using quasinormal modes, which represent the natural, dissipative eigenmodes o…
Multi-Photon Synthetic Lattices in Multi-Port Waveguide Arrays: Synthetic Atoms and Fock Graphs
Konrad Tschernig, Roberto de J. León-Montiel, Armando Perez-Leija +1
Activating transitions between internal states of physical systems has emerged as an appealing approach to create lattices and complex networks. In such a scheme, the internal stat…
Endurance of Quantum Coherence in Born-Markov Open Quantum Systems
Armando Perez-Leija, Diego Guzman-Silva, Roberto de J. Leon-Montiel +5
Quantum coherence, the physical property underlying fundamental phenomena such as multi-particle interference and entanglement, has emerged as a valuable resource upon which exotic…
Limitations of Particle-Based Spasers
Günter Kewes, Kathrin Herrmann, Rogelio RodrÃguez-Oliveros +3
We present a semi-classical analytic model for spherical core-shell surface plasmon lasers. Within this model, we drop the widely used one-mode approximations in favor of fully ele…
Two-photon edge states in photonic topological insulators: topological protection versus degree of entanglement
Konrad Tschernig, Alvaro Jimenez-Galan, Demetrios N. Christodoulides +4
Topological insulators combine insulating properties in the bulk with scattering-free transport along edges, supporting dissipationless unidirectional energy and information flow e…
Topological Protection in non-Hermitian Haldane Honeycomb Lattices
Pablo Reséndiz-Vázquez, Konrad Tschernig, Armando Perez-Leija +2
Topological phenomena in non-Hermitian systems have recently become a subject of great interest in the photonics and condensed-matter communities. In particular, the possibility of…
Influence of random surface deformations on the resonance frequencies and quality factors of optical cavities and plasmonic nanoparticles
Philip Trøst Kristensen, Thomas Kiel, Kurt Busch +1
Surface deformations of optical cavities and plasmonic nanoparticles are inevitable in nanophotonics. The random morphology changes of different realizations modify the associated…
Optical convolutional neural network with atomic nonlinearity
Mingwei Yang, Elizabeth Robertson, Luisa Esguerra +2
Due to their high degree of parallelism, fast processing speeds and low power consumption, analog optical functional elements offer interesting routes for realizing neuro-morphic c…
Thermalization of quantum light induced by classical nonlinear wave dynamics
Fouad Chahrour, Åahin K. Ozdemir, Kurt Busch +2
Thermalization of isolated quantum systems is an intriguing phenomenon at the forefront of contemporary physics. In this work, we demonstrate that nonlinear multimode optical platf…
Quantum thermodynamics of overdamped modes in local and spatially dispersive materials
Daniel Reiche, Kurt Busch, Francesco Intravaia
The quantum thermodynamical properties of (quasi-normal) overdamped electromagnetic modes (eddy currents) are investigated in the context of the magnetic Casimir-Polder interaction…
A fully nanoscopic dielectric laser
Günter Kewes, Rogelio Rodriguez-Oliveros, Kathrin Höfner +3
In this article, we introduce the concept of a dielectric nanolaser that is nanoscopic in all spatial dimensions. Our proposal is based on dielectric nanoparticles of high refracti…
Numerical evaluation of Casimir forces using the discontinuous Galerkin time-domain method
Carles Martà Farrà s, Bettina Beverungen, Philip Trøst Kristensen +2
We present a time-domain scheme for computing Casimir forces within the Maxwell stress tensor formalism, together with a specific realization using the finite-element-based discont…
Green's Function Formalism for Waveguide QED Applications
Michael P. Schneider, Tobias Sproll, Christina Stawiarski +2
We present a quantum-field-theoretical framework based on path integrals and Feynman diagrams for the investigation of the quantum-optical properties of one-dimensional waveguiding…
The Casimir-Polder interaction between atoms and hollow-core fibers
Bettina Beverungen, Daniel Reiche, Kurt Busch +1
The Casimir-Polder force acts on polarizable particles due to quantum fluctuations of the electromagnetic field that are modified by the presence of material bodies. We investigate…
Roadmap on Nonlocality in Photonic Materials and Metamaterials
Francesco Monticone, N. Asger Mortensen, Antonio I. Fernández-DomÃnguez +63
Photonic technologies continue to drive the quest for new optical materials with unprecedented responses. A major frontier in this field is the exploration of nonlocal (spatially d…
Two-particle quantum correlations in stochastically-coupled networks
Roberto de J. León-Montiel, Vicenç Méndez, Mario A. Quiroz-Juárez +4
Quantum walks in dynamically-disordered networks have become an invaluable tool for understanding the physics of open quantum systems. In this work, we introduce a novel approach t…
Modal expansions in periodic photonic systems with material loss and dispersion
Christian Wolff, Kurt Busch, N. Asger Mortensen
We study bandstructure properties of periodic optical systems composed of lossy and intrinsically dispersive materials. To this end, we develop an analytical framework based on adj…
The importance of substrates for the visibility of "dark" plasmonic modes
Saskia Fiedler, Søren Raza, Ruoqi Ai +5
Dark plasmonic modes have interesting properties, such as a longer lifetime and a narrower linewidth than their radiative counterpart, as well as little to no radiative losses. How…
Radiating dipoles in photonic crystals
Kurt Busch, Nipun Vats, Sajeev John +1
The radiation dynamics of a dipole antenna embedded in a Photonic Crystal are modeled by an initially excited harmonic oscillator coupled to a non--Markovian bath of harmonic oscil…
Multiphoton Discrete Fractional Fourier Dynamics in Waveguide Beam Splitters
Konrad Tschernig, Roberto de J. Leon-Montiel, Omar S. Magana-Loaiza +3
We demonstrate that when a waveguide beam splitter (BS) is excited by N indistinguishable photons, the arising multiphoton states evolve in a way as if they were coupled to each ot…
Electron beams traversing spherical nanoparticles: analytic and numerical treatment
P. Elli Stamatopoulou, Wenhua Zhao, Ãlvaro RodrÃguez Echarri +4
We present an analytic, Mie theory-based solution for the energy-loss and the photon-emission probabilities in the interaction of spherical nanoparticles with electrons passing nea…
Fluorescence in nonlocal dissipative periodic structures
Francesco Intravaia, Kurt Busch
We present an approach for the description of fluorescence from optically active material embedded in layered periodic structures. Based on an exact electromagnetic Green's tensor…
Nonequilibrium Casimir-Polder Force: Magnus-like Effect
Maria Vittoria Gurrieri, Kurt Busch, Francesco Intravaia
The motion of a particle in vacuum near macroscopic bodies gives rise to a Magnus-like contribution to the nonequilibrium Casimir-Polder force. This effect originates from the inte…
Nonadditive Enhancement of Nonequilibrium Atom-Surface Interactions
Daniel Reiche, Kurt Busch, Francesco Intravaia
The motion-induced drag force acting on a particle moving parallel to an arrangement of objects is analyzed. Particular focus is placed on the nonequilibrium statistics of the…
Fluorescence enhancement by dark plasmon modes
Manuel Peter, Julia F. M. Werra, Cody Friesen +3
We investigate the fluorescence properties of colloidal quantum dots attached to gold rod nanoantennas. These structures are fabricated by a two step electron beam lithography proc…
Quantization of quasinormal modes for open cavities and plasmonic cavity-QED
Sebastian Franke, Stephen Hughes, Mohsen Kamandar Dezfouli +4
We introduce a second quantization scheme based on quasinormal modes, which are the dissipative modes of leaky optical cavities and plasmonic resonators with complex eigenfrequenci…
Time- and frequency-domain study for electron beams penetrating dielectric nanospheres: fingerprints of Cherenkov and transition radiation
Wenhua Zhao, Christos Tserkezis, N. Asger Mortensen +1
We present a theoretical study of Cherenkov and transition radiation for swift electron beams penetrating dielectric nanospheres using material models of different sophistication.…
Time-integration of Gaussian variational approximation for the magnetic Schrödinger equation
Malik Scheifinger, Kurt Busch, Marlis Hochbruck +1
In the present paper we consider the semiclassical magnetic Schrödinger equation, which describes the dynamics of charged particles under the influence of a electro-magnetic field…
Wading through the void: Exploring quantum friction and nonequilibrium fluctuations
Daniel Reiche, Francesco Intravaia, Kurt Busch
When two or more objects move relative to one another in vacuum, they experience a drag force which, at zero temperature, usually goes under the name of quantum friction. This cont…
Mode-independent quantum entanglement for light
Jan Sperling, Armando Perez-Leija, Kurt Busch +1
We address the problem of the persistence of entanglement of quantum light under mode transformations, where orthogonal modes define the parties between which quantum correlations…
Relativistic electron energy-loss spectroscopy in cylindrical waveguides and holes
Ãlvaro RodrÃguez Echarri, Wenhua Zhao, Kurt Busch +1
Swift electrons passing near or through metallic structures have proven to be an excellent tool for studying plasmons and other types of confined optical modes involving collective…
In der Unruhe liegt die Kraft
Francesco Intravaia, Daniel Reiche, Kurt Busch
Fluctuations are ubiquitous in nature. They are one of the fundamental building blocks of quantum mechanics and are responsible for a wide variety of phenomena in many areas of phy…
A near-field study on the transition from localized to propagating plasmons on 2D nano-wedges
Thorsten Weber, Thomas Kiel, Stephan Irsen +2
In this manuscript we report on a near-feld study of two-dimensional plasmonic gold nano-wedges using electron energy loss spectroscopy in combination with scanning transmission el…
Far-off-resonant wave interaction in one-dimensional photonic crystals with quadratic nonlinearity
Johannes-Geert Hagmann, Lasha Tkeshelashvili, Kurt Busch +1
We extend a recently developed Hamiltonian formalism for nonlinear wave interaction processes in spatially periodic dielectric structures to the far-off-resonant regime, and invest…
Determining graphene's induced band gap with magnetic and electric emitters
Julia FM Werra, Peter Krüger, Kurt Busch +1
We present numerical and analytical results for the lifetime of emitters in close proximity to graphene sheets. Specifically, we analyze the contributions from different physical c…
Nonequilibrium Thermodynamics of Quantum Friction
Daniel Reiche, Francesco Intravaia, Jen-Tsung Hsiang +2
Thermodynamic principles are often deceptively simple and yet surprisingly powerful. We show how a simple rule, such as the net flow of energy in and out of a moving atom under non…
Entangled Two-Photon Absorption Spectroscopy with Varying Pump Wavelength
Lutz Mertenskötter, Kurt Busch, Roberto de J. León-Montiel
In virtual-state spectroscopy, information about the energy-level structure of an arbitrary sample is retrieved by Fourier transforming sets of measured two-photon absorption proba…
Design study of random spectrometers for applications at optical frequencies
Paris Varytis, Dan-Nha Huynh, Wladislaw Hartmann +2
Compact spectrometers based on disordered planar waveguides exhibit a rather high resolution with a relatively small footprint as compared to conventional spectrometers. This is ac…
Few-photon transport in low-dimensional systems: Interaction-induced radiation trapping
Paolo Longo, Peter Schmitteckert, Kurt Busch
We present a detailed analysis of the dynamics of photon transport in waveguiding systems in the presence of a two-level system. In these systems, quantum interference effects gene…
Cavity optomechanics with ultra-cold Bose gases for quasiparticle state manipulation and prospects for sensing applications
Benjamin MaaÃ, Daniel Hartley, Kurt Busch +1
Ensembles of ultra-cold atoms have been proven to be versatile tools for high precision sensing applications. Here, we present a method for manipulation and readout of the state of…
Optimal stellar rank approximation of squeezed cat states with photon catalysis
Julian K. Nauth, Nathan Walk, Ananga M. Datta +4
Non-Gaussian quantum states and operations constitute essential resources for achieving quantum computational advantage and enabling quantum error correction in bosonic platforms.…
All-optical switching, bistability, and slow-light transmission in photonic crystal waveguide-resonator structures
Sergei F. Mingaleev, Andrey E. Miroshnichenko, Yuri S. Kivshar +1
We analyze the resonant linear and nonlinear transmission through a photonic crystal waveguide side-coupled to a Kerr-nonlinear photonic crystal resonator. Firstly, we extend the s…
Real-time surface plasmon polariton propagation in silver nanowires
Wenhua Zhao, Ãlvaro RodrÃguez Echarri, Alberto Eljarrat +7
Electron microscopy techniques such as electron energy-loss spectroscopy (EELS) facilitate the spatio-spectral characterization of plasmonic nanostructures. In this work, a time-de…
Two-Particle Tight-Binding Description of Higher-Harmonic Generation in Semiconductor Nanostructures
Ulf Peschel, Thomas Lettau, Stefanie Gräfe +1
We develop a quantum mechanical theory to describe the optical response of semiconductor nanostructures with a particular emphasis on higher-order harmonic Generation. Based on a t…
Halevi's extension of the Euler-Drude model for plasmonic systems
Gino Wegner, Dan-Nha Huynh, N. Asger Mortensen +2
The nonlocal response of plasmonic materials and nanostructures is usually described within a hydrodynamic approach which is based on the Euler-Drude equation. In this work, we rec…
Branching high-order exceptional points in non-hermitian optical systems
Konrad Tschernig, Kurt Busch, Demetrios N. Christodoulides +1
Exceptional points are complex-valued spectral singularities that lead to a host of intriguing features such as loss-induced transparency - a counterintuitive process in which an i…
Nonequilibrium atom-surface interaction with lossy multi-layer structures
Marty Oelschläger, Kurt Busch, Francesco Intravaia
The impact of lossy multi-layer structures on nonequilibrium atom-surface interactions is discussed. Specifically, the focus lies on a fully non-Markovian and nonequilibrium descri…
Endurance of quantum coherence due to particle indistinguishability in noisy quantum networks
Armando Perez-Leija, Diego Guzmán-Silva, Roberto de J. León-Montiel +5
Quantum coherence, the physical property underlying fundamental phenomena such as multi-particle interference and entanglement, has emerged as a valuable resource upon which modern…
High-accuracy Casimir-Polder force calculations using the Discontinuous Galerkin Time-Domain method
Philip Trøst Kristensen, Bettina Beverungen, Francesco Intravaia +1
We describe a numerical time-domain approach for high-accuracy calculations of Casimir-Polder forces near micro-structured materials. The use of a time-domain formulation enables t…
Localization effects from local phase shifts in the modulation of waveguide arrays
Konrad Tschernig, Armando Perez-Leija, Kurt Busch
Artificial gauge fields enable the intriguing possibility to manipulate the propagation of light as if it were under the influence of a magnetic field even though photons possess n…
Time-domain modeling of interband transitions in plasmonic systems
Max Pfeifer, Dan-Nha Huynh, Gino Wegner +3
Efficient modeling of dispersive materials via time-domain simulations of the Maxwell equations relies on the technique of auxiliary differential equations. In this approach, a mat…
Exceptional points of any order in a single, lossy, waveguide beamsplitter by photon-number-resolved detection
Mario A. Quiroz-Juárez, Armando Perez-Leija, Konrad Tschernig +5
Exceptional points (EPs) are degeneracies of non-Hermitian operators where, in addition to the eigenvalues, corresponding eigenmodes become degenerate. Classical and quantum photon…
Strongly coupled slow-light polaritons in one-dimensional disordered localized states
Jie Gao, Sylvain Combrie, Baolai Liang +8
Cavity quantum electrodynamics advances the coherent control of a single quantum emitter with a quantized radiation field mode, typically piecewise engineered for the highest fines…
Odd and even photon-subtracted two-mode squeezed vacuum states
Ananga Mohan Datta, Kurt Busch, Armando Perez-Leija
Photon-subtracted two-mode squeezed vacuum states, a significant quantum resource, exhibit intricate correlations and unique quantum properties. In this work, we propose a theoreti…
Direct observation of the particle exchange phase of photons
Konrad Tschernig, Chris Müller, Malte Smoor +5
Quantum theory stipulates that if two particles are identical in all physical aspects, the allowed states of the system are either symmetric or antisymmetric with respect to permut…
Surface roughness in finite element meshes
Fabian Loth, Thomas Kiel, Kurt Busch +1
We present a practical approach for constructing meshes of general rough surfaces with given autocorrelation functions based on the unstructured meshes of nominally smooth surfaces…
Two-particle four-point correlations in dynamically disordered tight-binding networks
Armando Perez-Leija, Roberto de J. Leon-Montiel, Jan Sperling +3
We use the concept of two-particle probability amplitude to derive the stochastic evolution equation for two-particle four-point correlations in tight-binding networks affected by…