Back to shameless self-promotion duty: David Brady's new book "Computational Optical Imaging" cites our work! It's the only kind of citation I care about now—from people I respect and admire doi.org/10.1117/3.10...

Confirmed talk schedule for 3rd Workshop on Quantum Metrology and Quantum-Inspired Superresolution over Zoom next week: blog.nus.edu.sg/mankei/qisr26/. Topics from fundamental theory to on-sky demos. Registration is free! Deadline tomorrow.

I don't understand why quantum information theorists are freaking out about AI doing their math. It's like getting a washing machine to do laundry. The ultimate goal of these applied mathematicians is the "applied" part, right? Right?

Fun fact: pseudo-inverses for Hilbert-space operators are called Tseng inverses, named after Yuan-Yung Tseng, generalizing the Moore–Penrose inverse for matrices. zh.wikipedia.org/zh-hk/%E6%9B... No relation to me, although I used his inverse in my latest work.

I think I'm finally done with the paper. Will post to arXiv shortly.

The use of the Kalman filter in the Apollo navigation computer was hailed as a great success story, but I doubt that the actual scenario was anywhere close to the linear Gaussian model assumed by Kalman, or the filter achieved anything close to the theoretical error. (1/2)

Try as he might, the tail probability of survival is upper-bounded. (Sorry but couldn't resist)

Lance Fortnow@lance.fortnow.com · 3w ago

Herman Chernoff passed on July 6, shortly after turning 103 years old.

Theorists are like midfielders and experimentalists are like forwards. The art of a proposal, like a through ball, is to play it a little bit ahead of them into the open space, with the right direction and pace so that it matches their run and meets them at the right time.

www.timeshighereducation.com/news/kariko-...

Karikó: ‘scientists publish when they have nothing to say’

Nobel winner and mRNA vaccine pioneer criticises career-driven publications that lack scientific novelty

timeshighereducation.com

I invented a new method to numerically compute quantum Cramer-Rao bounds for semiparametric problems. I was hoping that it'd give tighter bounds than an old method, but I can't help but laugh when I see the result.

Easy to keep gravity classical in a consistent quantum model—assume it *measures* the rest of universe to estimate the stress-energy tensor. Hard part is narrow down the measurement model; any backaction probably too weak to observe experimentally in our lifetime (fig from a 2014 talk)

arxiv.org/abs/2606.18025 On-sky demo of SPADE for binary-source hypothesis testing. They introduced a 1-cm aperture to reduce turbulence effect, but clear advantage observed and an encouraging step.

On-sky binary source hypothesis testing beyond the diffraction limit using spatial mode demultiplexing based detection

Improving the resolution of telescope systems will provide the opportunity to study new physical phenomena in previously unobserved environments. Spatial mode de-multiplexing (SPADE) based imaging is ...

arxiv.org

Tentative schedule of the 3rd Workshop on Quantum Metrology and Quantum-Inspired Superresolution is posted at blog.nus.edu.sg/mankei/qisr26/. Stellar list of invited speakers from theory to experiments in microscopy and astronomy. Still a few slots for contributed talks on 4 Aug.

The first startup based on quantum-inspired superresolution? "rather than treating the scene as a blurry picture on a sensor, Guha’s method treats the arriving light itself as the ‘thing’ to be measured via quantum mathematics." www.defenseone.com/technology/2...

Quantum cameras could remake space-based intelligence

A Boston startup is getting ready to test a new imagery method for orbital satellites.

defenseone.com

Kudos to the experimentalists.

Physics Magazine@physicsmagazine.aps.org · 3mo ago

The performance of accelerometers, gravitational-wave detectors, and other light-based sensors is limited by unavoidable quantum noise. Now a team has built a tabletop device that reduces quantum noise by modifying a light beam before using it to make a measurement.

I'm deeply saddened that, when I google "BCH", it's now full of results about bitcoin cash and not Baker–Campbell–Hausdorff.

arxiv.org/abs/2605.10767 A new review paper on quantum-inspired superresolution. Thanks to my co-authors, who did all the heavy lifting.

Passive optical superresolution at the quantum limit

For more than a century, the diffraction limit has defined the resolution achievable by passive optical imaging systems. Although some resolution improvement can be gained through classical data proce...

arxiv.org

blog.nus.edu.sg/mankei/qisr26/ The 3rd Workshop on Quantum Metrology and Quantum-Inspired Superresolution will be held tentatively on 4-7 Aug over Zoom. The present edition will broaden the scope to encompass the general field of Quantum Metrology. Please register and share.

quantumzeitgeist.com/quantum-nois... Surprised that this website chooses to feature this paper of ours. Anyway I'd like to clarify that the improvement of spectral photon counting over homodyne is not limited to 30%, as claimed there. Not sure where they got that number from. (1/2)

Researchers Evaluate Quantum Limits To Noise Spectroscopy With Finite Observation Times

Spectrum analysis with quantum dynamical systems. II. Finite-time analysis Prior calculations suggested improved noise spectroscopy was possible with spectral photon counting, but relied on effectivel...

quantumzeitgeist.com

I wrote a blog post explaining my recent preprint. I wonder if it is now a waste of time to write these myself and AI may do a better job, but writing from scratch is still more enjoyable than proof-reading someone else's writing. blog.nus.edu.sg/mankei/2026/...

doi.org/10.1073/pnas... With all due respect to Sir John Pendry and I've only glanced at the paper, but this is just spontaneous parametric down conversion.

Dirac visited Singapore (then part of Malaysia; the now-NUS campus was part of U. of Malaya) on 2nd March 1955. Our physics department treats this photo as a treasure, but for him it's not the most pleasant trip. [excerpt from Dirac's biography by Farmelo]

More than two decades after Google introduced a game called Google Scholar that has taken the academia by storm, we finally have a winner.

arxiv.org/abs/2604.00413 Following the on-sky demo of superresolution by SPADE last year, there's now a demo using fluorophores by Warwick Bowen's group, achieving 40nm resolution. Still early days, but amazing experimental progress in both telescopy and microscopy.

Structured detection microscopy

Super-resolution microscopy is crucial for imaging sub-wavelength biological structures. However, most techniques rely on nonlinear saturation or stochastic switching of emitters, limiting imaging spe...

arxiv.org

To achieve the ultimate Holevo-Nagaoka bound for quantum multiparameter estimation, people have used a lot of fancy math to describe the measurement, but it offers little clue what the experiment would look like. This work proposes a more physical scheme. arxiv.org/abs/2603.17955

Approaching the ultimate limit of quantum multiparameter estimation by many-body physics

I propose a physical measurement scheme on multiple independent and identically distributed quantum objects to approach the Holevo--Nagaoka bound for quantum multiparameter estimation. The scheme enta...

arxiv.org

www.nature.com/articles/s41... I've been saying that entanglement-assisted stellar interferometry is unlikely to become practical in my lifetime, but that won't stop me from shamelessly claiming a little bit of credit every time others make heroic progress in this direction.

Entanglement-assisted non-local optical interferometry in a quantum network - Nature

Entangled quantum memories are used in a quantum network of silicon–vacancy centres in diamond nanocavities to experimentally perform non-local phase measurements.

nature.com

www.science.org/doi/10.1126/..., www.science.org/doi/10.1126/... STO has a Pockels coefficient >30x that of lithium niobate at cryogenic temperature. Sounds like a miracle.

Quantum critical electro-optic and piezo-electric nonlinearities

Although electro-optic (EO) nonlinearities are essential for many quantum and classical photonics applications, a major challenge is inefficient modulation in cryogenic environments. Guided by the con...

science.org

Is QCMC dead as well?

"This theory is going to revolutionize the car industry... We assume that the road is a frictionless plane and we won't study what happens when there is friction. We also perform a demo using superfluids." This is what a lot of quantum metrology papers look like to me.