Adaptive variational algorithms for quantum Gibbs state preparation

Understand

The preparation of Gibbs thermal states is an important task in quantum computation with applications in quantum simulation, quantum optimization, and quantum machine learning.

• However, many algorithms for preparing Gibbs states rely on quantum subroutines which are difficult to implement on near-term hardware.
• Here, we address this by (i) introducing an objective function that, unlike the free energy, is easily measured, and (ii) using dynamically generated, problem-tailored ans\"atze.
• This allows for arbitrarily accurate Gibbs state preparation using low-depth circuits.