[Paper Review] Non-Thermal Aging of Supercooled Liquids in Optical Cavities

Muhammad R. Hasyim, Arianna Damiani+1 more|arXiv (Cornell University)|Mar 16, 2026

Material Dynamics and Properties0 citations

TL;DR

The paper demonstrates that placing a supercooled liquid inside an optical cavity induces non-thermal aging by selectively pumping vibrational modes, effectively cooling the structure and slowing aging without heating the bath.

ABSTRACT

Aging is a hallmark of disordered materials such as glasses, plastics, and pharmaceuticals, where it often limits long-term stability and performance. In practice, aging is controlled through global parameters like temperature or pressure, which act uniformly on the entire system. Here we introduce a fundamentally different approach, using light confined in optical cavities as a precise and selective tool to guide aging dynamics. We show that a supercooled liquid coupled to an optical cavity undergoes non-thermal aging, where aging is induced by light without a thermal quench. Light selectively pumps fast vibrational modes while the bath temperature remains unchanged, reshaping the slow structural dynamics of the liquid. The cavity-coupled liquid thereby behaves as if it were structurally colder than its surroundings. Exploiting this effective structural cooling together with the timescale separation, we introduce cavity configurational feedback ($\mathrm{C^2F}$) cooling, which uses cavity coupling to reach progressively lower structural temperatures. Our results establish a connection between glass physics and strong light-matter interactions and open a new route toward optical control of aging, glass formation, and nonequilibrium materials dynamics.

Motivation & Objective

• Motivate a new approach to aging control in disordered materials using light in optical cavities instead of thermodynamic state changes.
• Show that strong light–matter coupling selectively excites vibrational modes and reshapes slow structural dynamics without changing bath temperature.
• Demonstrate that aging under cavity coupling follows universal glassy relaxation behavior predictable from equilibrium data via fictive temperatures.
• Introduce a protocol (Cavity Configurational Feedback, C2F) to progressively access lower structural temperatures using cavity-driven energy exchange.

Proposed method

• Model a dipole-active extension of the Kob–Andersen glass-former confined in a Fabry–Pérot cavity and simulate with cavity molecular dynamics.
• Verify strong coupling via IR spectra showing Rabi splitting and polariton formation.
• Analyze aging via the intermediate scattering function and define structural relaxation time to quantify cavity-induced slowdown.
• Map potential-energy changes to vibrational and structural fictive temperatures using equilibrium relations and Rosenfeld–Tarazona scaling.
• Reconstruct a material time hλ(t) under different coupling strengths and waiting times using a regularized least-squares framework.
• Apply Tool–Narayanaswamy (TN) aging model to connect cavity-driven dynamics to equilibrium relaxation data.

Experimental results

Research questions

• RQ1 Can strong light–matter coupling in an optical cavity non-thermally alter aging dynamics of a supercooled liquid without changing bath temperature?
• RQ2 How does the cavity affect the separation of timescales between fast vibrational dynamics and slow structural relaxation?
• RQ3 Can aging under cavity coupling be described by time-reparameterization and mapped to equilibrium aging concepts like fictive temperature?
• RQ4 Is it possible to design feedback protocols (C2F) that exploit cavity-induced cooling to reach lower configurational states?
• RQ5 Do cavity-driven aging dynamics collapse onto universal aging trajectories similar to thermally quenched glasses?

Key findings

• Stronger light–matter coupling slows structural relaxation in the cavity, with a waiting-time dependent slowdown indicative of aging.
• The slowdown persists for up to ~2.5 ns and remains even off-resonance, showing robustness of non-thermal aging.
• Vibrational fictive temperature rises while structural fictive temperature drops below bath temperature, signaling non-thermal cooling of the structural subsystem.
• Normalized ISFs collapse onto a universal master curve under material-time reparameterization, with a stretched-exponential form Φk(h)=e−hβ and β≈0.55.
• Tool–Narayanaswamy modeling quantitatively reproduces the observed cavity-driven aging by using equilibrium relaxation data evaluated at the instantaneous fictive temperature.
• C2F cooling can drive a system from room temperature to a glassy state (~32 K) by cyclic cavity activation and bath-temperature feedback, achieving rapid configurational cooling.