# Coherent macroscopic quantum tunneling in boson-fermion mixtures

## TL;DR

This paper predicts that in cold atom systems with Bose-Einstein condensates and fermionic atoms, the BEC can coherently tunnel between separated and mixed states, offering a new platform to study macroscopic quantum tunneling.

## Contribution

Theoretical demonstration of coherent macroscopic quantum tunneling in BEC-fermion mixtures, with specific predictions for experimental parameters and observable oscillations.

## Key findings

- Coherent oscillations of BEC in fermionic environment predicted
- Period, amplitude, and dissipation rate calculated for specific isotopes
- Potential for experimental observation discussed

## Abstract

We show that the cold atom systems of simultaneously trapped Bose-Einstein condensates (BEC's) and quantum degenerate fermionic atoms provide promising laboratories for the study of macroscopic quantum tunneling. Our theoretical studies reveal that the spatial extent of a small trapped BEC immersed in a Fermi sea can tunnel and coherently oscillate between the values of the separated and mixed configurations (the phases of the phase separation transition of BEC-fermion systems). We evaluate the period, amplitude and dissipation rate for $^{23}$Na and $^{40}$K-atoms and we discuss the experimental prospects for observing this phenomenon.