Shintaro Minagawa

Entanglement in von Neumann Algebraic Quantum Information Theory In quantum systems with infinitely many degrees of freedom, states can be infinitely entangled across a pair of subsystems, but are there different forms of infinite entanglement? To understand entang...

Interested in entanglement theory for systems with infinitely many degrees of freedom? Take a look at my PhD thesis, now available on the arXiv 🥳 arxiv.org/abs/2510.07563

We will hold the workshop "Quantum Foundations" from March 5, 2026 to March 6, 2026 at The University of Osaka (Toyonaka):
qsys.se.shibaura-it.ac.jp/kimura/QFoun...

So far, this workshop has been held as a hybrid of on-site and online, with most sessions in Japanese, but one in English.

Contextuality in Anomalous Heat Flow For a class of quantum systems that exhibit contextuality, a rigorous theoretical connection between anomalous heat flow and quantumness is established, thereby opening avenues to explore nonclassical...

New paper out in #PRX_Quantum! 📃📃

We show when a heat-flow reversal is actually a signature of quantum nonclassicality as described by quantum generalized contextuality.

#QuantumInformation #Contextuality #Nonclassicality #QuantumThermodynamics

journals.aps.org/prxquantum/a...

A structure theorem for complex-valued quasiprobability representations of physical theories Quasiprobability representations are well-established tools in quantum information science, with applications ranging from the classical simulability of quantum computation to quantum process tomograp...

scirate.com/arxiv/2509.1...

New preprint out! We extend existing structure theorems for quasiprobability representations of general probabilistic theories to allow for complex-valued ones.

量子力学100周年研究会：量子基礎・量子情報のこれまでとこれから 2025/08/07    ポスター発表についてのページを追加しました。2025/07/23 オンライン参加に限り参加登録を再開しました。2025/07/19 参加登録を締め切りました。2025/07/15 現地参加の登録を締め切りました。2025/07/05 旅費補助の申請を締め切りました。2025/06/16 講演タイトルを掲載しました。2025/05/30 Webページ、参加登録、発表申込フ...

This is the link but it was a completely domestic workshop in Japan, so no English version
indico.yukawa.kyoto-u.ac.jp/event/64/

I organized a workshop that celebrates the 100th anniversary of quantum mechanics at Kyoto University in Japan. We invited a lot of researchers who lead fields that relate to quantum foundations, for example, universe, condensed matter, statistical mechanics, history of science, experiments, etc.

I visited Komaba Campus, the University of Tokyo

We all have a favorite characterization of the thermal state: as an equilibrium state, via a maximum entropy principle, from the resource theory of thermodynamics, as a step in learning algorithms, among others.

What is the analogous concept for quantum channels?

🎉 We've got an answer! ⚛️ 🧪

👇

A fun project with Seok Hyung, Jeongrak ( @perp-waterfall.bsky.social ), @nellynghy.bsky.social , and Paul Boes. We dusted off some old notes because there seemed to be renewed interest in what differentiates thermal operations from Gibbs-preserving maps.

arxiv.org/abs/2507.16637

I am looking for a PhD student to explore quantum advantage with indistinguishable particles in my group at CTP PAS, Warsaw (within Quantera TouQan project touqan.eu). 4‑yr scholarship, start  Oct 2025. Apply by 8 Aug 2025: euraxess.ec.europa.eu/jobs/360583

More on Intractability of Thermalization: (almost) i.i.d. inputs and finite lattices This work is an extention of Shiraishi and Matsumoto [10], and discusses the computational complexity of the long-term average of local observables in one-dimensional lattices with shift-invariant nea...

arxiv.org/abs/2507.02601

I would be happy to be added to this list!

Copyright by Alexander Rommel / TU Wien.

What started as informal discussions on the Danube beach in Vienna during QTD2023 has been published at last. Trying to come up with an experimentally feasible quantum clock we came across a rich model – the ring clock – that overturned a common wisdom in the community. doi.org/10.1038/s415...

Energy-Limited Quantum Dynamics - Communications in Mathematical Physics We consider quantum systems with energy constraints relative to a reference Hamiltonian. In general, quantum channels and continuous-time dynamics need not satisfy energy conservation. Physically mean...

My paper Energy-limited quantum dynamics was published in CMP! 🎉

doi.org/10.1007/s002...

I'll do a short thread when I find the time for it.

Thank you!
I will do my best to make my research life in Europe a fruitful one.

Thank you!
I am happy to have this opportunity and I will do my best.

Optimum testing of multiple hypotheses in quantum detection theory The problem of specifying the optimum quantum detector in multiple hypotheses testing is considered for application to optical communications. The quantum digital detection problem is formulated as a ...

What is the earliest use of SDPs in quantum mechanics? I am aware of the seminal 1975 work of Yuen-Kennedy-Lax

ieeexplore.ieee.org/document/105...

on multiple quantum hypothesis testing. Was there something earlier? One might think so, given that the q postulates are specified by SDP constraints.

I became a postdoctoral researcher at Aix-Marseille Université in France.

High-temperature partition functions and classical simulability of long-range quantum systems Long-range quantum systems, in which the interactions decay as $1/r^α$, are of increasing interest due to the variety of experimental set-ups in which they naturally appear. Motivated by this, we stud...

Very excited to show the first paper of my first PhD student! We prove that long-range models have well-behaved partition functions at high temperatures (despite being all-to-all coupled!), and we build sub-exponential time classical algorithms for their approximation: arxiv.org/abs/2504.20901

Macroscopic states and operations: a generalized resource theory of coherence To understand the emergence of macroscopic irreversibility from microscopic reversible dynamics, the idea of coarse-graining plays a fundamental role. In this work, we focus on the concept of macrosco...

Introducing our resource theory of microscopicity: a unifying framework where macroscopic entropy meets Bayesian retrodiction, Petz recovery maps, quantum coherence, athermality, etc. Everything can be understood as "inferential asymmetry" or "irretrodictability".

arxiv.org/abs/2504.12738

YouTube video by Francesco Buscemi The Petz map in maths, information theory, and physics: an overview

Since I gave an overview presentation on the Petz transpose map in 2021, we've learned a lot more about its interpretation and relation to Bayesian inversion. The most important, in my opinion, is the derivation of the Petz transpose map from a principle of minimum change.

youtu.be/8ZzGI7hYAfU

General, efficient, and robust Hamiltonian engineering Implementing the time evolution under a desired target Hamiltonian is critical for various applications in quantum science. Due to the exponential increase of parameters in the system size and due to ...

We provide an efficient method to engineer arbitrary many-body Hamiltonians also robust against various dominant errors.
I will present these results next Wednesday at #QCTIP2025.
arxiv.org/abs/2410.19903

A complete theory of the Clifford commutant The Clifford group plays a central role in quantum information science. It is the building block for many error-correcting schemes and matches the first three moments of the Haar measure over the unit...

🧵 Super excited to finally share our new paper 🎉

Together with the dream team- Lennart Bittel,
@jenseisert.bsky.social, Lorenzo Leone, @sfeoliviero.bsky.social - we present a full theory of the Clifford commutant ⚡, a central object in quantum information. ⚛️

📄 arxiv.org/abs/2504.12263

Artificially intelligent Maxwell's demon for optimal control of open quantum systems

iopscience.iop.org/article/10.1...

A reinforcement learning agent in #machinelearning is interpreted literally as a thermodynamic agent reminiscent of a #Maxwell's demon for the control of open quantum systems.

We’re organising a conference in Dublin! Fundamental Limits of Quantum Technologies 2025 — everything from error mitigation on NISQ devices, through control constraints on complex quantum systems, to quantum thermodynamics and energetics, and much more! Abstract submission and registration open! 👇

PIS Laboratory at University of Tsukuba - Seminar / Visitors Join the mailing list on the seminar announcement [here].

I gave a seminar on thermodynamics and incompatibility of quantum measurement processes at my lab:
sites.google.com/view/pis-uni...

I became a postdoctoral fellow at University of Tsukuba. Wonderful campus surrounded by nature and many lively students.

ありがとうございます！私が量子統計などいろいろ勉強中のとき、Xでいろいろ教えてくださりありがとうございました。

Thank you very much, Jake! I look forward to another interesting discussion with you someday!

On March 25th, 2025, I received my PhD.
The PhD course is a precious memory, including the difficult days. I was able to progress with the help of many people, especially my wonderful supervisor @quantumquia.com . I am glad that I was able to look at my diploma with a smile at the end.