Capturing an Electron in the Virtual State

Authors

• Alok Nath Singh, University of Rochester
• Bibek Bhandari, Chapman University
• Rafael Sánchez, Universidad Autónoma de Madrid
• Andrew N. Jordan, Chapman UniversityFollow

Document Type

Article

Publication Date

7-13-2026

Abstract

We address a foundational question in quantum mechanics: can a particle be directly found in a classically-forbidden virtual state? We instantiate this conceptual question by investigating the traversal of electrons through a tunnel barrier, which we define in a triple quantum dot system where the occupation of the central dot is energetically avoided. The motivation behind this setup is to answer whether the central dot is occupied or not during a virtual transition when it is being explicitly monitored. We investigate this problem in two different limits of continuous measurements: the stochastic quantum diffusion and the quantum jump. We find that, even though individual trajectories differ considerably across these limits, measuring leads to a higher occupation in the central dot on average. We also find that a suitably strong measurement can significantly boost the tunneling current—an effect we call measurement-assisted tunneling. Our results demonstrate that the act of observation fundamentally reshapes tunneling dynamics, resolving the seeming paradox of detecting a particle in a classically forbidden region: weak measurements partially localize the particle, while strong measurements enforce a discontinuous either/or detection or no detection outcome.

Comments

This article was originally published in New Journal of Physics, volume 28, in 2026. https://doi.org/10.1088/1367-2630/ae846a

Recommended Citation

Singh AN, Bhandari B, Sánchez R, and Jordan AN 2026 New J. Phys. 28 074503. https://doi.org/10.1088/1367-2630/ae846a

Peer Reviewed

1

Copyright

The authors

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 License.