Efficient A-enhanced Gray Molasses Using an Electromagnetically-Induced-transparency-based Laser Locking Scheme

We present a low-cost implementation of lambda-enhanced gray molasses cooling in a nonstandard beam geometry and with an inexpensive laser locking setup that only provides limited coherence of the Raman laser beams. In contrast to the established use of resource-intensive phase-locking methods, our laser system uses two independent lasers, frequency- locked to a spectral feature produced by an electromagnetically induced transparency (EIT) resonance. We show that this approach achieves sufficient coherence to enable effective gray molasses cooling without the need for costly GHz electronics, significantly reducing the complexity and cost of experimental setups and represents a step toward more accessible cold atom technologies. Furthermore, the cooling remains efficient even with a nonoptimal beam geometry, typical of cold-atoms quantum computing platforms based on optical tweezers. A wave-function Monte Carlo analysis supports the experimental findings, offering insight into the cooling dynamics of this unconventional scheme.