Sirui Lu

Sirui Lu he/him

陆思锐

Physics for AI · AI for Physics

I’m a physics PhD candidate at the Max Planck Institute of Quantum Optics and TU Munich, advised by J. Ignacio Cirac — dissertation submitted, defense on November 9, 2026. I work at the intersection of quantum many-body physics and machine learning: physics for AI, and AI for physics.

My work runs in two directions. I build AI methods for quantum science: quantum simulation and algorithms, neural and tensor-network quantum states, and agent-driven discovery of quantum error-correcting codes. And I use physics and information theory to study AI: tensor networks and stochastic thermodynamics applied to modern generative models.

I also build the tools. I created TeXRA, a multi-agent research assistant for theorists that grounds LLM reasoning in Wolfram algebra and Lean 4 proof. I used it to co-design 14,116 certified quantum codes. With Max Welling and Lars Holdijk I co-authored Generative AI and Stochastic Thermodynamics (Cambridge University Press, 2026).

I am looking for research roles at industry AI labs and academic postdoc positions. Get in touch.

Selected publications

all publications →

Algorithms for Quantum Simulation at Finite Energies

Sirui Lu, Mari Carmen Bañuls, J. Ignacio Cirac,
PRX Quantum 2, 020321 2021
Abstract
We introduce two kinds of quantum algorithms to explore microcanonical and canonical properties of many-body systems. The first is a hybrid quantum algorithm that, given an efficiently preparable state, computes expectation values in a finite energy interval around its mean energy, using a filtering operator similar to quantum phase estimation and recovering physical values through interferometric measurements. Its computational time scales polynomially with the number of qubits, the inverse variance, and the inverse error, and it does not require long-time evolution. The second is a quantum-assisted Monte Carlo sampling method for microcanonical and canonical ensemble quantities that circumvents the sign problem of classical quantum Monte Carlo. Both can run on small quantum computers and analog quantum simulators.
Cite
@article{Lu2021Algorithms,
  title = {Algorithms for Quantum Simulation at Finite Energies},
  author = {Lu, Sirui and Ba{\~n}uls, Mari Carmen and Cirac, J. Ignacio},
  year = 2021,
  month = may,
  journal = {PRX Quantum},
  volume = {2},
  number = {2},
  pages = {020321},
  doi = {10.1103/prxquantum.2.020321}
}

Multi-agent Autoformalization of Tensor Network Theory

Sirui Lu, Erickson Tjoa, J. Ignacio Cirac,
arXiv:2607.07857 2026
Abstract
We build a team of specialized large language-model agents and present an agent-driven workflow for research-level formalization in theoretical physics, with the autoformalization of the fundamental theorem of matrix-product states as a demonstration. The agents, coordinated through a structured mathematical blueprint and periodic human review, orchestrated and executed the full formalization autonomously. For some statements, the agents were able to explore new proof routes that are not part of the standard literature. Along the way the agents produced extensive tensor-network and quantum-information libraries not previously available in Mathlib, Lean's mathematical library. As a physical application, the formalization also extends towards symmetry-protected topological phases in one dimension. We find that the main bottleneck in large-scale autoformalization is enforcing mathematical intent and we provide a detailed study of the full process and various subtleties involved. We release the codebase as the library TNLean, together with a chapter-by-chapter blueprint of the formalization effort.
Cite
@misc{Lu2026Multi,
  title = {Multi-agent Autoformalization of Tensor Network Theory},
  author = {Lu, Sirui and Tjoa, Erickson and Cirac, J. Ignacio},
  year = 2026,
  month = jul,
  eprint = {2607.07857},
  archiveprefix = {arXiv},
  primaryclass = {quant-ph}
}
🏆 Oral at NeurIPS 2025 AI4Science

Can Theoretical Physics Research Benefit from Language Agents?

Sirui Lu, Zhijing Jin, Terry Jingchen Zhang, Pavel Kos, Bernhard Schölkopf
ICML 2026 2026
Abstract
Large Language Models (LLMs) are rapidly advancing across diverse domains, yet their application in theoretical physics remains inadequate. While current models show competence in mathematical reasoning and code generation, we identify critical gaps in physical intuition, constraint satisfaction, and reliable reasoning that cannot be addressed through prompting alone. Physics demands approximation judgment, symmetry exploitation, and physical grounding that require AI agents specifically trained on physics reasoning patterns and equipped with physics-aware verification tools. We envision physics-specialized AI agents that handle multimodal data, propose physically consistent hypotheses, and autonomously verify theoretical results, and we call for collaborative efforts between physics and AI communities to build the specialized infrastructure necessary for AI-driven scientific discovery.
Cite
@misc{Lu2025Can,
  title = {Can Theoretical Physics Research Benefit from Language Agents?},
  author = {Lu, Sirui and Jin, Zhijing and Zhang, Terry Jingchen and Kos, Pavel and Cirac, J. Ignacio and Sch{\"o}lkopf, Bernhard},
  year = 2026,
  month = jun,
  eprint = {2506.06214},
  archiveprefix = {arXiv},
  primaryclass = {cs.CL}
}
🏆 Editors' Suggestion

Tensor Networks and Efficient Descriptions of Classical Data

Sirui Lu, Márton Kanász-Nagy, Ivan Kukuljan, J. Ignacio Cirac,
Phys. Rev. A 111, 032409 2025
Abstract
We investigate the potential of tensor network based machine learning methods to scale to large image and text data sets. For that, we study how the mutual information between a subregion and its complement scales with the subsystem size L, similarly to how it is done in quantum many-body physics. We find that for text, the mutual information scales as a power law with a close to volume law exponent, indicating that text cannot be efficiently described by 1D tensor networks. For images, the scaling is close to an area law, hinting that 2D tensor networks such as PEPS could have adequate expressibility. For the numerical analysis, we introduce a mutual information estimator based on autoregressive networks, and we also use convolutional neural networks in a neural estimator method.
Cite
@article{Lu2025Tensor,
  title = {Tensor Networks and Efficient Descriptions of Classical Data},
  author = {Lu, Sirui and {Kan{\'a}sz-Nagy}, M{\'a}rton and Kukuljan, Ivan and Cirac, J. Ignacio},
  year = 2025,
  month = mar,
  journal = {Phys. Rev. A},
  volume = {111},
  number = {3},
  pages = {032409},
  doi = {10.1103/PhysRevA.111.032409}
}

Selected projects

all projects →

Generative AI and Stochastic Thermodynamics

- Present

A book with Max Welling and Lars Holdijk on the free-energy unification of generative AI and stochastic thermodynamics. Cambridge University Press, July 2026.

Generative AIStochastic thermodynamicsFree energy

TNLean: tensor networks, formally verified

- Present

Multi-agent autoformalization of tensor-network theory in Lean 4 / Mathlib: the fundamental theorem of matrix-product states, machine-checked.

Lean 4MathlibTensor networksFormal methods

TeXRA: Multi-agent AI for theorists

- Present

Multi-agent AI research assistant (VS Code / Cursor / CLI) that grounds LLM reasoning in Wolfram algebra and Lean 4 formal proof.

LLM agentsTypeScriptLean 4WolframVS Code

News

Submitted my PhD dissertation to TU Munich. The defense is scheduled for November 9, 2026.