University of Basel researchers bridge quantum and semiclassical thermodynamics

Physicists at the University of Basel have developed a theoretical framework that bridges the gap between quantum and semiclassical thermodynamics. The research focuses on driven-dissipative quantum systems, specifically a model involving an atom trapped between two mirrors in a cavity.

In these systems, an atom absorbs and emits light, creating a continuous flow of energy. A key challenge in quantum thermodynamics is distinguishing between energy that acts as disordered “heat” and energy that remains coherent and capable of performing useful work. The researchers found that treating all escaping light as waste heat can distort the thermodynamic description of cavity quantum-electrodynamics (QED) systems.

By separating orderly, coherent light from noisy fluctuations, the team demonstrated that quantum thermodynamics can consistently align with its simpler semiclassical limit. This distinction is expected to assist in more accurate detection of quantum behavior and could enable highly precise measurements by utilizing reduced light fluctuations in quantum devices.