Achieving electrical conductance in amorphous non-doped polymers is a challenging task. In my talk, I present how a serendipitous experiment led us to the finding that the vibrational strong coupling (VSC) of amorphous polymers such as polystyrene, deuterated polystyrene, poly (benzyl methacrylate), and a few other polystyrene derivatives enhance the electrical conductance by orders of...
Molecular vibrations can couple to optical cavities to create new hybrid states called polaritons. Under such conditions, one may realize modified materials processes such as photon emission, molecular energy transfer, and chemical reaction rates. In this talk, I will first discuss modeling and active control of cavity coupling to molecular vibrations. Next, I will discuss measurements of...
We present recent ab-intio simulation results for matter strongly dressed by optical cavities. Our focus will be on the relevance of classical and quantum features emergent from the vibrational strong coupling to the vacuum field fluctuations at finite temperature. The role and description of cavity induced non-canoncial equilibrium condition for chemical systems, as well as the relevance of...
Current efforts for implementing cavity QED in the ultrastrong coupling (USC) regime using molecular vibrations in mid-infrared nanoresonators opens exciting opportunities for exploring novel chemical reactivities that exploit quantum correlations with the electromagnetic vacuum at room temperature. While most theoretical studies have primarily focused on rationalizing previous experimental...
A planar Fabry-Perot cavity is studied at the deep-subwavelength inter-mirror distances, termed "zeroth-cavity mode". Enhanced transmission is observed as d→0 using time-domain terahertz spectroscopy.
The observed modification of thermal chemical rates in Fabry-Perot cavities
remains poorly understood. Mounting evidence supported by theory indicates that
the cavity has a small effect on the potential energy barrier, suggesting that
dynamical corrections may play a prominent role. This is in line with the
relatively small modifications of the rate constant usually reported, often...
Theoretically explaining experimental observations of cavity-modified physics and chemistry remains to be a major challenge, in particular for a large number of coupled emitters (N). Here I discuss a bottom-up approach with minimal quantum many-body models, which include electronic, photonic, and motional degrees of freedom in their simplest form. Solving these (already complex) many-body...
Various experiments have demonstrated that strong collective interaction influences chemical reactivity -- it remains to build a conclusive understanding.
Certain aspects such as a resonant behaviour, specific trends in the thermodynamic observables, and a strong sensitivity to the solvent have been identified as critical.
Capturing those effects in a consistent theoretical model is...
In many of the envisaged applications of strong coupling, especially polaritonic chemistry, open access to the molecules involved is vital, as is independent control over polariton dispersion, and spatial uniformity of the coupling. Existing cavity designs are not able to offer all of these advantages simultaneously. Here we demonstrate an alternative yet simple cavity design that exhibits all...
Through the strong coupling of molecular vibrational modes with photonic modes, intriguing molecular vibrational polariton states and dark reservoir modes emerge. These polaritons, exhibiting a dual nature of matter and light, have the potential to modify chemical reactions under thermally activated conditions, paving the way for the emerging field of polariton chemistry. Distinguishing...
Recent numerical experiments on (a) consequences of vibrational strong coupling (b) polariton propagation and (c) manifestation of collective molecular response in optical cavities will be presented and discussed.
Noble-metal nanostructures support collective electron resonances, known as plasmons, that can “squeeze” optical fields down to nanometer-scale volumes, well below the conventional diffraction limit. The strong localization of electromagnetic fields greatly enhances nonlinear optical processes, both in the metal nanostructure itself and in adjacent optical materials. Because the processes...
The effect of vibrational strong coupling of water on the ionic conductivity is discussed. Modification of the ionic transport in aqueous electrolyte solutions depends on the hydration structures, showing improved conductivities than those based on the classical interpretation.
Over the past two decades, we have achieved a high degree of mastery in studying fundamental nano-optical interactions between single molecules and single photons. These include controlled coherent experiments in the near field, far-field demonstration of efficient extinction, various nonlinear measurements and single-molecule strong coupling in a microcavity. More recently, we have pursued...
The theoretical description of molecular polaritons and their properties is still subject to many open questions. In the past years we studied a variety of effects, such as dissipation, to determine its influence on the photochemistry. More recently we have implement Hartree-Fock with the cavity Born-Oppenheimer approximation to investigate the multi-molecule effects in the electronic ground...
Cooperative effects in complex, coupled quantum systems, cannot be understood by sole consideration of the individual constituents, as they arise from the interplay among them. Light-matter platforms provide an optimal playground for the observation and exploitation of quantum cooperative effects [1]. For example, structured subwavelength arrays of quantum emitters trapped in optical lattices,...
In this presentation, I will review some recent experimental [1,2] and theoretical attempts [3,4] to design innovative electromagnetic cavities for chiral-sensing purposes or polaritonic chemistry. In particular, I will focus on the interplay between the degree of polarization of the optical cavitymode and the intra-cavity light-matter interactions, exhibiting some difficulties to enhance...
Here we show the effective photon-free QEDFT approach works well
in the strong coupling regime and requires the ‘suppression’ factor
and electron-photon correlation potential in the weak coupling
regime. We apply the approach to 1D, 2D, and 3D one-electron finite
systems to focus on the electron-photon interaction.
Single organic molecules in the solid-state are one of the promising optical platforms for realizing quantum networks owing to their remarkable coherent properties and flexibility in their chemical synthesis. However, the molecular excited states associated with the strong Fourier-limited zero-phonon lines of these systems decay within nanoseconds, posing a challenge for practical applications...
We derived and implemented relativistic QEDFT in linear response regime. The electrons are treated at the four-component Dirac–Kohn–Sham level of theory and coupled to transverse photons treated as dynamical variables. We show that light–matter coupling can enhance the strength of usually weak singlet–triplet transitions via a new type of spin–orbit interaction mediated by cavity photons.
