Speeding Up Particle Slowing using Shortcuts to Adiabaticity

TL;DR

This paper introduces a rapid particle slowing method using shortcuts to adiabaticity with laser pulses, reducing momentum efficiently without typical diffusion, especially beneficial for narrow-linewidth systems like molecules.

Contribution

The authors develop a shortcut to adiabaticity approach for particle slowing that minimizes momentum diffusion and is effective for systems lacking closed cycling transitions.

Findings

Potential to slow particles to near rest in less than a millimeter

Advantages over traditional radiation pressure methods when excited state decay is small

Effective for narrow-linewidth systems such as certain molecules

Abstract

We propose a method for slowing particles by laser fields that potentially has the ability to generate large forces without the associated momentum diffusion that results from the random directions of spontaneously scattered photons. In this method, time-resolved laser pulses with periodically modified detunings address an ultranarrow electronic transition to reduce the particle momentum through repeated absorption and stimulated emission cycles. We implement a shortcut to adiabaticity approach that is based on Lewis-Riesenfeld invariant theory. This affords our scheme the advantages of adiabatic transfer, where there can be an intrinsic insensitivity to the precise strength and detuning characteristics of the applied field, with the advantages of rapid transfer that is necessary for obtaining a short slowing distance. For typical parameters of a thermal oven source that generates a particle beam with a central velocity on the order of meters per second, this could result in slowing the particles to near stationary in less than a millimeter. We compare the slowing scheme to widely-implemented slowing techniques that rely on radiation pressure forces and show the advantages that potentially arise when the excited state decay rate is small. Thus, this scheme is a particularly promising candidate to slow narrow-linewidth systems that lack closed cycling transitions, such as occurs in certain molecules.