# Novel Technique for Robust Optimal Algorithmic Cooling

## TL;DR

This paper introduces a new, simpler, and more robust technique for heat-bath algorithmic cooling that can reach the cooling limit without prior state knowledge, making HBAC more practical for quantum tech.

## Contribution

A novel fixed-operation method for HBAC that simplifies implementation and approaches the theoretical cooling limit without needing state information.

## Key findings

- Converges to the asymptotic HBAC state
- More feasible and robust implementation of HBAC
- Potentially exponential iterations needed for saturation

## Abstract

Heat-bath algorithmic cooling (HBAC) provides algorithmic ways to improve the purity of quantum states. These techniques are complex iterative processes that change from each iteration to the next and this poses a significant challenge to implementing these algorithms. Here, we introduce a new technique that on a fundamental level, shows that it is possible to do algorithmic cooling and even reach the cooling limit without any knowledge of the state and using only a single fixed operation, and on a practical level, presents a more feasible and robust alternative for implementing HBAC. We also show that our new technique converges to the asymptotic state of HBAC and that the cooling algorithm can be efficiently implemented; however, the saturation could require exponentially many iterations and remains impractical. This brings HBAC to the realm of feasibility and makes it a viable option for realistic application in quantum technologies.