Jekyll2026-03-01T22:11:13-08:00https://threeplusone.com/feed.xmlThe physics of informationGavin E. Crooks2099-01-01T00:00:00-08:002099-01-01T00:00:00-08:00https://threeplusone.com/news/upcoming<p><img src="/assets/images/upcoming.png" alt="Upcoming" /></p> <h3 id="amica-conference-thermodynamic-approaches-to-artificial-intelligence"><a href="https://thermo-ai.riken.jp/amica.html">Amica Conference: Thermodynamic Approaches to Artificial Intelligence</a></h3> <p>March 9-11, 2026, Karuizawa, Japan</p>Gavin E. Crooks

Amica Conference: Thermodynamic Approaches to Artificial Intelligence. March 9-11, 2026, Karuizawa, Japan.

2026-03-01T00:00:00-08:002026-03-01T00:00:00-08:00https://threeplusone.com/pubs/on-info-009-0.10<p>A brief overview of information measures on classical, discrete probability distributions.</p> <p>PDF: <a href="/info">https://threeplusone.com/info</a></p> <p>Source: <a href="https://github.com/gecrooks/on_information/releases/tag/v0.10.0">https://github.com/gecrooks/on_information</a></p> <p><br /><br /> <a href="/info" class="align-right"><img src="/assets/images/info.png" alt="info" /></a></p> <h2 id="release-notes">Release Notes</h2> <p>v0.10 (2026-03-01)</p> <p>Added index; Miscellaneous minor improvements.</p> <p>v0.9 (2024-03-02)</p> <p>v0.8 (2021-12-10)</p> <p>v0.7 (2018-09-22)</p> <p>v0.6 (2017-05-07)</p> <p>v0.5 (2016-08-16)</p> <p>v0.4 (2016-06-22)</p> <p>v0.3 (2016-04-21)</p> <p>v0.2 (2015-06-26)</p> <p>v0.1 (2015-01-22)</p>Gavin E. Crooks

A brief overview of information measures on classical, discrete probability distributions.

2026-02-21T00:00:00-08:002026-02-21T00:00:00-08:00https://threeplusone.com/pubs/on-gates-v0.12<p>Notes on the circuit model of quantum computing. Currently mostly an exposition on the menagerie of quantum gates.</p> <p>PDF: <a href="/gates">https://threeplusone.com/gates</a></p> <p>Source: <a href="https://github.com/gecrooks/on_gates/releases/tag/v0.12.0">https://github.com/gecrooks/on_gates</a></p> <p><br /><br /> <a href="/gates" class="align-right"><img src="/assets/images/weyl_3d.png" alt="weyl" /></a></p> <h2 id="release-notes">Release Notes</h2> <p>v0.12 (2026-02-21)</p> <p>Extensive review of all chapters fixing 100+ spelling, grammar, and math errors. Notable math fixes include: power series signs, CPhase canonical coordinates, Swap-alpha exponents, Hadamard conjugation matrices, XYX/XZX Clifford results, Clifford group product formula, multiplexed gate decomposition formulas, T gate phase, and two-level decomposition normalization. Fixed cross-references and citations.</p> <p>v0.11 (2024-07-25)</p> <p>v0.10 (2023-05-26)</p> <p>v0.9 (2023-03-01)</p> <p>v0.8 (2022-02-14)</p> <p>v0.7 (2022-01-12)</p> <p>v0.6 (2021-07-24)</p> <p>v5 (2020-11-17)</p> <p>v4 (2020-06-03)</p> <p>v3</p> <p>v2</p> <p>v1 (2019-05-01)</p>Gavin E. Crooks

Notes on the circuit model of quantum computing. Currently mostly an exposition on the menagerie of quantum gates.

2026-02-17T00:00:00-08:002026-02-17T00:00:00-08:00https://threeplusone.com/pubs/Crooks2026a<p>Gavin E. Crooks</p> <p>arXiv:2602.15392</p> <p>[ <a href="https://arxiv.org/pdf/2602.15392">Full text</a> | <a href="https://arxiv.org/abs/2602.15392">arXiv</a> ]</p>Gavin E. Crooks

The relative entropy of a non-equilibrium ensemble to the corresponding equilibrium ensemble is the excess free energy.

2026-01-01T00:00:00-08:002026-01-01T00:00:00-08:00https://threeplusone.com/pubs/Donatella2026a<p>Kaelan Donatella, Samuel Duffield, Maxwell Aifer, Denis Melanson, Gavin Crooks, Patrick J. Coles</p> <p>npj Unconventional Computing, 3(1):5 (2026)</p> <p>[ <a href="/pubs/Donatella2026a.pdf">Full text</a> | <a href="https://doi.org/10.1038/s44335-025-00049-x">Journal</a> | <a href="https://arxiv.org/abs/2405.13817">arXiv</a> ]</p>Gavin E. Crooks

We show that natural gradient descent can have a similar computational complexity per iteration to a first-order method, when employing appropriate hardware.

2025-07-14T00:00:00-07:002025-07-14T00:00:00-07:00https://threeplusone.com/media/acm-thermodynamic-computing<p><a href="/assets/images/normalizer.png" class="align-right"><img src="/assets/images/normalizer.png" alt="Normalizer" /></a></p> <p>Samuel Greengard, Communications of the ACM, July 14, 2025</p> <p><a href="https://cacm.acm.org/news/thermodynamic-computing-becomes-cool/">Original article</a></p>Gavin E. Crooks

Communications of the ACM article on thermodynamic computing and Normal Computing.

2025-07-14T00:00:00-07:002025-07-14T00:00:00-07:00https://threeplusone.com/pubs/compute-crisis<p>Maxwell Aifer, Zach Belateche, Suraj Bramhavar, Kerem Y. Camsari, Patrick J. Coles, Gavin Crooks, Douglas J. Durian, Andrea J. Liu, Anastasia Marchenkova, Antonio J. Martinez, Peter L. McMahon, Faris Sbahi, Benjamin Weiner, Logan G. Wright</p> <p>arXiv:2507.10463</p> <p>[ <a href="https://arxiv.org/pdf/2507.10463">Full text</a> | <a href="https://arxiv.org/abs/2507.10463">arXiv</a> ]</p>Gavin E. Crooks

Physics-based Application-Specific Integrated Circuits present a transformative paradigm by directly harnessing intrinsic physical dynamics for computation.

2025-05-19T00:00:00-07:002025-05-19T00:00:00-07:00https://threeplusone.com/media/ieee-spectrum-thermodynamic-computing<p><a href="/assets/images/normalizer.png" class="align-right"><img src="/assets/images/normalizer.png" alt="Normalizer" /></a></p> <p>Dina Genkina, IEEE Spectrum, May 19, 2025</p> <p><a href="https://spectrum.ieee.org/thermodynamic-computing-normal-computing">Original article</a></p>Gavin E. Crooks

IEEE Spectrum article on thermodynamic computing and Normal Computing.

2025-04-01T00:00:00-07:002025-04-01T00:00:00-07:00https://threeplusone.com/pubs/Melanson2025a<p>Denis Melanson, Mohammad Abu Khater, Maxwell Aifer, Kaelan Donatella, Max Hunter Gordon, Thomas Ahle, Gavin Crooks, Antonio J. Martinez, Faris Sbahi, Patrick J. Coles</p> <p>Nature Communications, 16(1):3757 (2025)</p> <p>[ <a href="/pubs/Melanson2025a.pdf">Full text</a> | <a href="https://doi.org/10.1038/s41467-025-59011-x">Journal</a> | <a href="https://arxiv.org/abs/2312.04836">arXiv</a> ]</p>Gavin E. Crooks

We present the first continuous-variable thermodynamic computer, which we call the stochastic processing unit (SPU).

2025-02-12T00:00:00-08:002025-02-12T00:00:00-08:00https://threeplusone.com/pubs/thermo-second-order<p>Kaelan Donatella, Samuel Duffield, Denis Melanson, Maxwell Aifer, Phoebe Klett, Rajath Salegame, Zach Belateche, Gavin Crooks, Antonio J. Martinez, Patrick J. Coles</p> <p>arXiv:2502.08603</p> <p>[ <a href="https://arxiv.org/pdf/2502.08603">Full text</a> | <a href="https://arxiv.org/abs/2502.08603">arXiv</a> ]</p>Gavin E. Crooks

We propose a scalable algorithm for employing thermodynamic computers to accelerate a popular second-order optimizer called K-FAC.