# Peering into the Anneal Process of a Quantum Annealer

## TL;DR

This paper introduces a slicing technique to monitor the evolution of solutions in a quantum annealer during the annealing process, providing new insights into qubit behavior and freeze-out points.

## Contribution

The study demonstrates how to track solution evolution in a quantum annealer using customizable anneal schedules, revealing qubit dynamics and freeze-out points.

## Key findings

- Identified when individual bits flip and stabilize during annealing
- Determined freeze-out points for each qubit
- Visualized solution evolution in optimized instances

## Abstract

Commercial adiabatic quantum annealers have the potential to solve important NP-hard optimization problems efficiently. The newest generation of those machines additionally allows the user to customize the anneal schedule, that is, the schedule with which the anneal fraction is changed from the start to the end of the annealing. In this work we use the aforementioned feature of the D-Wave 2000Q to attempt to monitor how the anneal solution evolves during the anneal process. This process we call slicing: at each time slice during the anneal, we are able to obtain an approximate distribution of anneal solutions. We use our technique to obtain a variety of insights into the D-Wave 2000Q. For example, we observe when individual bits flip during the anneal process and when they stabilize, which allows us to determine the freeze-out point for each qubit individually. We highlight our results using both random QUBO (quadratic unconstrained binary optimization) instances and, for better visualization, instances which we specifically optimize (using our own genetic algorithm) to exhibit a pronounced evolution of its solution during the anneal.