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  • Open Access

Time-Resolved and Superradiantly Amplified Unruh Effect

Akhil Deswal1,*, Navdeep Arya2,†, Kinjalk Lochan1, and Sandeep K. Goyal1

  • *Contact author: akhildeswal.phy@gmail.com
  • †Contact author: navdeep.arya@fysik.su.se, navdeeparya.me@gmail.com
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Phys. Rev. Lett. 135, 183601 – Published 27 October, 2025

DOI: https://doi.org/10.1103/6z1l-kkmk

Abstract

We identify low-acceleration conditions under which the Unruh effect manifests as an early superradiant burst in a collection of excited atoms. The resulting amplified Unruh signal is resolved from the inertial signal both in time and intensity. We demonstrate theoretically that these conditions are realized inside a subresonant cavity that highly suppresses the response of an inertial atom, while allowing significant response from an accelerated atom as, owing to the acceleration-induced spectral broadening, it can still couple to the available field modes. The setup thus selectively amplifies the modified field fluctuations underlying the Unruh effect into an early superradiant burst. In comparison, the field fluctuations perceived inertially would cause a superradiant burst much later. In this way, we simultaneously address the extreme acceleration requirement, the weak Unruh signal, and the dominance of the inertial signal, all within a single experimental arrangement.

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Phys. Rev. Lett. 135, 183601– Published 27 October, 2025
  • Received 16 February 2025
  • Accepted 1 October 2025
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