Research

What We Do...

The high-level vision of the Canada Excellence Research Chair (CERC) in Light-Matter Interactions is to deliver new knowledge on the properties of microscopic systems made of many interacting light-induced particles in the solid state, which will empower the discovery and implementation of new materials for photonics and quantum technologies.

These particles interact not only amongst themselves, but also with the noisy, complex environment in which they reside, and their quantum dynamics depend intrinsically in this many-partner dance with a moving dance floor.

In quantum emission, for example, in devices that emit light as single particles termed photons, it is critical to know whether emission occurs in a quantum-mechanical or classical regime, and it is further necessary to find means to manipulate and control the quantum state of light-matter excitations.

We are active in this level of fundamental materials physics. Specifically, our research addresses:

I

Mechanisms by which light-induced excited states interact in a complex, fluctuating, even co-evolving environment to determine the materials photophysical and optical properties.

II

Interactions between strongly mixed light-matter quasiparticles in photonic and optical devices.

III

Seeking optical signatures of ground-state entanglement in strongly correlated electron material, with an ultimate view of controlling such quantum state of matter for quantum technologies.

The CERC will develop innovative training and equity, diversity, and inclusion programs in parallel, and these will be an intrinsic part of the CERC research program.

Thrust 1

Spectroscopic Probes of Entanglement in Strongly Correlated Matter

How do primary photoexcitations interact with a noisy, complex environment and between each other? How do these many-body couplings drive the quantum dynamics that underpin optical properties? What are the optical signatures of ground-state spin-orbital entanglement in strongly correlated systems?

Develop coherent ultrafast non-linear spectroscopic techniques to probe many-body electronic, magnetic and vibrational correlations through excited state dynamics in well understood materials exhibiting correlated phases of matter (e.g. Mott Insulators and anti-ferromagnets).
Extend our investigation to the coherent non-linear response of materials exhibiting exotic physics such as high-temperature superconductors.
Develop gauge-appropriate theoretical tools to model light-matter interactions and quantum dynamics of excited states in highly correlated materials.
Develop phenomenological theoretical models of matter to guide the interpretation of coherent ultrafast non-linear spectra.
Screen for candidate materials exhibiting behavior indicative of a quantum spin liquid through their coherent non-linear optical response.
Explore novel material families for quantum spin liquid behavior.

Thrust 2

Polariton Many-Body Physics

How do many-body interactions in matter drive interactions between hybrid light-matter quasiparticles in the strong coupling regime? How do these quantum dynamics govern the formation of quantum ground states in photonic devices?

To measure exciton-polariton quantum dynamics with full momentum and spectral resolution by means of Fourier-space hyperspectral nonlinear (χ(3)) spectroscopic imaging, namely transient photoreflectance (TPR) and two-dimensional coherent transient photoreflectance (2D-TPR). Concomitantly, to isolate nonlinear population dynamics by means of Fourier-space hyperspectral imaging of excitation correlation photoluminescence (ECPL) transients

To resolve correlations induced by the dark-exciton reservoir, specifically multi-polariton and polariton-exciton correlations, by means of higher-order nonlinear (χ(5), χ(7)) two-dimensional coherent spectroscopy implementing a phase-matching, time-ordering experimental scheme.

To model theoretically coherent nonlinear spectral lineshapes measured in objectives 1 & 2 using QuDPy, a quantum dynamics tool to compute ultrafast non-linear optical responses. We will employ QuDPy to train a neuron network and subsequently decode experimental coherent nonlinear spectra in terms of specific many-body contributions.

Thrust 3

Interfaces

Can we exploit light-matter quantum dynamics for photonic technologies involving interactions of molecular moieties across interfaces?

The development of novel low-D materials and interfaces for electronics and optoelectronics will help maintaining an international leadership on quantum materials.

Using covalent grafting chemistry and nanometre-scale patterns, Prof. Martel and Prof. Bouilly from the CERC core team, have conducted various works over the last years targeting new quantum phenomena in 1D and 2D materials for enhancing light-matter interaction and chemical transduction.

In collaboration with Prof. Silva, this work will explore more specifically nanostructures made of graphene, nanotubes (CNTs) and other nanohybrid structures made of these building blocks. More specifically, the team aims to tailor optical resonances in 2D materials and graphene-based membranes.