Composite quantum systems as quantum clocks and thermometers

Abstract

Composite particles (like atoms and molecules) are unique tools for testing joint quantum and general relativistic effects. These particles are often described as ‘clocks’, in direct analogy to atomic clocks, however one could also think of them as ‘thermometers’, as they thermalise via coupling to external fields. Hence, one asks if we can use these particles to tease out quantum features of temperature, in analogy to how idealised clocks have been used to probe the quantum nature of time.

However, all studies of the free propagation of composite particles find that they delocalize into separate internal energy components, which destroys their spatial coherence, rendering them unsuitable for experimental applications and as idealized clocks. We solve this problem by introducing a class of states with minimum uncertainty in spacetime that fully overcome the delocalization. The relevant physics comes from minimizing the uncertainty between position and velocity, rather than position and momentum, while directly accounting for mass as an operator.

In this talk, I will introduce these new minimum uncertainty states and some of their unique properties. I will then discuss some of the groundwork we have laid for probing the quantum nature of temperature, by exploring two scenarios in which a ‘superposition of temperatures’ may arise.

Carolyn Wood

Postdoctoral Scientist

Carolyn Wood is a postdoctoral researcher at the University of Queensland, in Brisbane, Australia focusing on quantum machine learning and physics at the interface between quantum mechanics and general relativity.