Speaker
Description
Strong light–matter interactions span a wide range of questions, from the nature of the cavity itself (e.g., microcavities versus plasmonic cavities), to local versus collective coupling effects, and the distinction between classical and quantum behavior, to name just a few. In this talk, I will focus on two somewhat complementary perspectives that highlight these different facets.
First, I will present a classical viewpoint and show how cavities can be used to control aging in disordered materials. Aging is a defining feature of disordered materials such as glasses, plastics, and pharmaceuticals, often limiting long-term stability and performance. Whereas aging is typically controlled through global parameters such as temperature or pressure, here we show it can instead be tuned selectively using light. Specifically, when a supercooled liquid is coupled to an optical cavity, the system undergoes what we call non-thermal aging: aging induced by light without any change in temperature. Importantly, the cavity-coupled liquid behaves as if it were structurally colder than its surroundings, enabling a cavity cooling protocol.
Second, I will turn to a more quantum perspective and discuss the quantum–classical divide in polaritonic systems. Here we introduce a new feature, the twin polariton: an additional splitting beyond the primary polariton resonance that originates from vacuum field fluctuations. This feature can persist in the many-molecule limit under symmetric initial conditions, but most importantly follows the same linear dependence on coupling strength as the primary splitting. This establishes a novel mechanism by which a quantum feature (the twin polariton) can be tuned through a classical one (the primary polariton), offering new opportunities to probe and control the fundamental nature of polaritonic systems.