26th Australian Institute of Physics Congress and the Australian and New Zealand Conference on Optics and Photonics

Comparing Superpositions of Pointlike and Quantum CoM Particle Detectors

Not scheduled

20m

Belinda Hutchinson Building (The University of Sydney )

Contributed Oral AIP | Theoretical Physics (TPG)

Speaker

Carolyn Wood (The University of Queensland)

Description

Particle detector models are powerful tools for probing different quantum fields or spacetimes. The dominant model, the Unruh–DeWitt (UDW) detector, describes a pointlike particle interacting with a quantum field along a classical trajectory, with only the particle’s internal state treated as a quantum degree of freedom.Recent studies have moved to include more realistic quantum effects, describing standard UDW detectors in superpositions of classical trajectories[1,2], or upgrading the model to better capture the properties of physical systems such as atoms, with a quantised centre of mass (CoM) dynamically evolving under a non-relativistic Hamiltonian[3], and the introduction of mass-energy equivalence[4].

In this work, we compare superpositions of the standard pointlike UDW and quantum-CoM detector models, and explore under which limits and conditions one model can reasonably approximate the other. We indeed find regimes in which the quantum model approaches the classical, but also effects in the quantum-CoM case which the standard UDW model is not equipped to capture.

[1] J. Foo, S. Onoe, and M. Zych, "Unruh-deWitt detectors in quantum superpositions of trajectories," Phys. Rev. D 102, 085013 (2020).
[2] L. C. Barbado, E. Castro-Ruiz, L. Apadula, and Č. Brukner, "Unruh effect for detectors in superposition of accelerations," Phys. Rev. D 102, 045002 (2020).
[3] N. Stritzelberger and A. Kempf, "Coherent delocalization in the light-matter interaction," Phys. Rev. D 101, 036007 (2020).
[4] C. E. Wood and M. Zych, "Quantized mass-energy effects in an Unruh-DeWitt detector," Phys. Rev. D 106, 025012 (2022).