Quantum and classical algorithms for weakly interaction fermions at finite temperature

Quantum and classical algorithms for weakly interaction fermions at finite temperature

Formal & Physical Sciences Physics PHPhysicsPHUMathematical
🎙 Yu Tong 👥 42K 📅 January 13, 2026 ⏱ 46 min 👁 349 📄 original study 🧭 2026-08-13
Available in: English (current) Français

Keywords

quantum algorithmclassical algorithmfermionsfinite temperaturelog partition function

Summary

The talk by Yu Tong presents two algorithms for computing the log partition function of weakly interacting fermions at finite temperature. The first is a quantum algorithm based on Lindbladians, which prepares the Gibbs state and uses thermodynamic integration to compute the log partition function. The second is a classical algorithm based on cluster expansion and belief propagation. The talk begins by introducing the fermionic Hamiltonian and the problem of computing the log partition function. It discusses the trivial case of non-interacting fermions and the hardness for strong interactions, motivating the perturbative regime. The speaker explains the cluster expansion and the challenges of summing Feynman diagrams, leading to quasi-polynomial time algorithms. The quantum algorithm uses a Lindbladian with a proven mixing time bound, leveraging a parent Hamiltonian with a spectral gap. The classical algorithm uses cluster expansion and belief propagation to compute the log partition function directly. The talk concludes by comparing the two approaches and discussing potential quantum advantage.

160 words

Critical Evaluation

Value of the Information & Strength of the Argument

The talk provides valuable insights into both quantum and classical algorithms for a fundamental problem in quantum many-body physics. The argumentation is rigorous, with clear explanations of the mathematical techniques and complexity considerations. The speaker effectively motivates the problem and explains the challenges, such as the factorial growth of Feynman diagrams and the need for efficient sampling. The presentation of the quantum algorithm’s mixing time bound and the classical algorithm’s convergence is well-structured. The speaker also addresses questions from the audience, clarifying technical points.

Scientific Rigor, Source Quality, Title Accuracy

The talk demonstrates high scientific rigor, with references to prior work and clear statements of assumptions and results. The sources cited include the IPAM workshop page and the speaker’s own research. The title accurately describes the content. The talk is part of a scientific workshop, indicating a peer-reviewed context. The speaker is a recognized researcher in the field. The presentation is technical and assumes familiarity with quantum many-body physics, but the logic is clear.

173 words

Title / Content Match

The title accurately reflects the content: the talk presents both quantum and classical algorithms for weakly interacting fermions at finite temperature.

Quality & Reliability

8/10

The talk presents original research results with rigorous mathematical proofs, published in collaboration with recognized researchers. The speaker is a postdoc at Duke University, and the content is part of an IPAM workshop, indicating peer-reviewed context. However, the presentation is a talk, not a peer-reviewed paper, and some details are simplified.

Key Moments

Cited Sources

Concurring Sources

Contribution & Novelties

The talk presents two novel algorithms: a quantum algorithm with a proven mixing time bound for preparing Gibbs states of weakly interacting fermions, and a classical algorithm based on cluster expansion and belief propagation. These are significant contributions to the field, as they provide rigorous runtime guarantees for problems that were previously only heuristically solved. The quantum algorithm leverages a parent Hamiltonian with a spectral gap, while the classical algorithm avoids the factorial growth of Feynman diagrams.

Pour aller plus loin :

118 words

Radar Profile

The radar profile shows high scores in all dimensions, indicating a technically deep and reliable presentation. The talk is highly informative and rigorous, with a strong focus on original research.

Reliability 8/10

💬 No comments were provided for analysis.