Quantum particles passing through a matter-wave aperture

TL;DR

This paper theoretically examines how quantum particles passing through a matter-wave aperture behave at finite temperature, revealing non-monotonic detection patterns due to decoherence effects.

Contribution

It introduces a model accounting for environmental dissipation and predicts a novel valley-peak structure in particle detection as a function of distance.

Findings

Detection probability exhibits a valley-peak structure with distance.

The structure depends on wavelength, temperature, and aperture size.

Decoherence nonlocality causes the unusual pattern.

Abstract

We investigate theoretically a dilute stream of free quantum particles passing through a macroscopic circular aperture of matter-waves and then moving in a space at a finite temperature, taking into account the dissipative coupling with the environment. The portion of particles captured by the detection screen is studied by varying the distance between the aperture and the screen. Depending on the wavelength, the temperature, and the dimension of the aperture, an unusual local valley-peak structure is found in increasing the distance, in contrast to traditional thinking that it decreases monotonically. The underlying mechanism is the nonlocality in the process of decoherence for an individual particle.