Skip to main content

Research Repository

Advanced Search

The cost of building a wall for a fermion

Wan Mokhtar, Wan Mohamad Husni; Louko, Jorma

The cost of building a wall for a fermion Thumbnail


Wan Mohamad Husni Wan Mokhtar

Professor of Mathematical Physics


We analyse the energy cost of building or demolishing a wall for a massless Dirac field in (1+1)-dimensional Minkowski spacetime and the response of an Unruh-DeWitt particle detector to the generated radiation. For any smoothly-evolving wall, both the field’s energy density and the detector’s response are finite. In the limit of rapid wall creation or demolition, the energy density displays a delta function squared divergence. By contrast, the response of an Unruh-DeWitt detector, evaluated within first-order perturbation theory, diverges only logarithmically in the duration of the wall evolution. The results add to the evidence that a localised matter system may not be as sensitive to the rapid wall creation as the local expectation values of field observables. This disparity has potential interest for quantum information preservation scenarios.


Wan Mokhtar, W. M. H., & Louko, J. (2022). The cost of building a wall for a fermion. Journal of High Energy Physics, 2022(8), Article 69.

Journal Article Type Article
Acceptance Date Jul 1, 2022
Online Publication Date Aug 4, 2022
Publication Date Aug 1, 2022
Deposit Date Aug 5, 2022
Publicly Available Date Aug 8, 2022
Journal Journal of High Energy Physics
Electronic ISSN 1029-8479
Publisher Springer Science and Business Media LLC
Peer Reviewed Peer Reviewed
Volume 2022
Issue 8
Article Number 69
Keywords Nuclear and High Energy Physics
Public URL
Publisher URL


You might also like

Downloadable Citations