Trapping and binding by dephasing

TL;DR

This paper demonstrates that particle trapping and binding can be achieved through spatially dependent dephasing, a form of decoherence, rather than traditional conservative forces, with practical implementations suggested for cold Rydberg atoms.

Contribution

It introduces a novel mechanism for particle trapping and binding using dephasing, expanding the understanding of decoherence effects in quantum systems.

Findings

Dephasing can induce particle trapping in a quantum particle-in-the-box.

Dephasing enables binding of two particles despite repulsive interactions.

Practical realization with Rydberg atoms in cold gases is feasible.

Abstract

The binding and trapping of particles usually rely on conservative forces, described by unitary quantum dynamics. We show that both can also arise solely from spatially dependent dephasing, the simplest type of decoherence. This can be based on continuous weak position measurements in only selected regions of space, for which we propose a practical realisation. For a single particle, we demonstrate a quantum particle-in-the-box based on dephasing. For two particles, we demonstrate their binding despite repulsive interactions, if their molecular states are dephased at large separations only. Both mechanisms are experimentally accessible, as we show for an example with Rydberg atoms in a cold gas background.