Runaway evaporation for optically dressed atoms

TL;DR

This paper proposes a novel optical evaporation scheme using an optical knife in two-electron atoms, enabling independent control of evaporation and potentially leading to more efficient cooling of quantum gases.

Contribution

Introduction of an optical knife method for forced evaporation that operates independently of trap confinement, improving cooling efficiency in quantum gas experiments.

Findings

Potential to achieve runaway evaporation regime

Enhanced cooling efficiency in two-electron atom systems

Comparison with existing methods considering three-body losses

Abstract

Forced evaporative cooling in a far-off-resonance optical dipole trap is proved to be an efficient method to produce fermionic- or bosonic-degenerated gases. However in most of the experiences, the reduction of the potential height occurs with a diminution of the collision elastic rate. Taking advantage of a long-living excited state, like in two-electron atoms, I propose a new scheme, based on an optical knife, where the forced evaporation can be driven independently of the trap confinement. In this context, the runaway regime might be achieved leading to a substantial improvement of the cooling efficiency. The comparison with the different methods for forced evaporation is discussed in the presence or not of three-body recombination losses.