Ahsan Nazir

Florian Mintert

Quantum thermodynamics in the strong coupling regime

The four laws of classical thermodynamics are so enshrined at the heart of our understanding of nature that they govern how we as physicists intuitively expect physical systems should behave. If we come across a situation that appears to violate one of the laws of thermodynamics, it can feel very wrong. No experiment has ever produced reproducible results that contradict one of the four laws.

However, these laws are based on empirical evidence for how macroscopic systems behave, and we have so far been unable to derive a version of thermodynamics based on quantum mechanics, which is currently our best guess for a theory that predicts how microscopic systems behave.

My project forms a small part of the current search for a quantum mechanical theory of thermodynamics. Carnot, one of the pioneers of classical thermodynamics, was able to formulate the second law by studying the way energy flowed between a system and a reservoir in a heat engine. I’m interested in whether the same approach might be possible in the quantum regime. Can we define heat, work and entropy flow in the case of a quantum system interacting with a thermal reservoir? How do some of the weird and wonderful aspects of quantum theory such as entanglement, non-locality and coherence change the way we understand the workings of a quantum heat engine? And will we find that classical thermodynamics is really a theory that emerges from a more fundamental version, teeming with strange and counterintuitive behaviour that only quantum mechanics allows us to uncover?