Mankei Tsang
@mankei-tsang.bsky.social
Associate Professor at the National University of Singapore. Quantum Metrology, Quantum Optics, Superresolution. https://blog.nus.edu.sg/mankei/
"On-sky Demonstration of Subdiffraction-limited Astronomical Measurement Using a Photonic Lantern." I haven't read the paper yet, but this sounds exciting. iopscience.iop.org/article/10.3... newsroom.ucla.edu/releases/tel...
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iopscience.iop.org
October 25, 2025 at 5:57 PM
"On-sky Demonstration of Subdiffraction-limited Astronomical Measurement Using a Photonic Lantern." I haven't read the paper yet, but this sounds exciting. iopscience.iop.org/article/10.3... newsroom.ucla.edu/releases/tel...
When I review a bad paper but try to stay diplomatic
October 22, 2025 at 3:02 PM
When I review a bad paper but try to stay diplomatic
www.youtube.com/watch?v=MLh0... Stunning experiment of macroscopic quantum tunneling at room temperature! Widespread applications as well. (not trying to belittle the amazing Nobel achievement at all, just fun to point out)
TotalInternalReflection Fingerprint
YouTube video by Rainer Heintzmann
www.youtube.com
October 8, 2025 at 8:02 AM
www.youtube.com/watch?v=MLh0... Stunning experiment of macroscopic quantum tunneling at room temperature! Widespread applications as well. (not trying to belittle the amazing Nobel achievement at all, just fun to point out)
SQUID and superconducting circuits are cool, but with all due respect the benefit of quantum computing to mankind is not even net positive yet.
October 7, 2025 at 2:36 PM
SQUID and superconducting circuits are cool, but with all due respect the benefit of quantum computing to mankind is not even net positive yet.
The AI has spoken
October 5, 2025 at 7:36 PM
The AI has spoken
x.com/arxiv/status... We have this curious phenomenon that the number of papers is exploding in recent years, but Nobel prizes are more often going to older people and older work. What if quantity is negatively correlated with quality?
arXiv.org on X: "Days in a work week: 5 Days in a month: 30 Total new submissions to arXiv in September: 26,646 arXiv editorial and user support staff: 7 someone who is good at science please help me with this. our team isn't sleeping. #openaccess #preprints https://t.co/T5uFYohrUj" / X
Days in a work week: 5 Days in a month: 30 Total new submissions to arXiv in September: 26,646 arXiv editorial and user support staff: 7 someone who is good at science please help me with this. our team isn't sleeping. #openaccess #preprints https://t.co/T5uFYohrUj
x.com
October 4, 2025 at 8:03 AM
x.com/arxiv/status... We have this curious phenomenon that the number of papers is exploding in recent years, but Nobel prizes are more often going to older people and older work. What if quantity is negatively correlated with quality?
Reposted by Mankei Tsang
Putting my thoughts together. Why networks beat "hero" sensors and what birds can teach us.
quantum-noise.ghost.io/quantum-sens...
quantum-noise.ghost.io/quantum-sens...
Quantum Sensing Like a Bird
A few nights ago I was on a panel on Quantum Sensing for Defense. Preparing for this panel crystallized some ideas for me, which I think I should write down somewhere. So here it is!
When we talk abo...
quantum-noise.ghost.io
September 28, 2025 at 7:23 PM
Putting my thoughts together. Why networks beat "hero" sensors and what birds can teach us.
quantum-noise.ghost.io/quantum-sens...
quantum-noise.ghost.io/quantum-sens...
doi.org/10.1109/MSP.... Sad to learn that Van Trees passed away in 2023. His books are for me the perfect balance of principles and practice. For many years they were my secret recipe for my research—just pick a chapter and generalize to quantum.
In Remembrance of Dr. Harry L. Van Trees [In Memoriam]
Recounts the career and contributions of Dr. Harry L. Van Trees.
doi.org
September 26, 2025 at 3:28 PM
doi.org/10.1109/MSP.... Sad to learn that Van Trees passed away in 2023. His books are for me the perfect balance of principles and practice. For many years they were my secret recipe for my research—just pick a chapter and generalize to quantum.
Quantum Optics Lecture Notes v0.5: the main addition is Appendices K and L on the classical "semiparametric Cramer-Rao bound." (1/2)
www.ece.nus.edu.sg/stfpage/tmk/...
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www.ece.nus.edu.sg/stfpage/tmk/...
www.ece.nus.edu.sg/stfpage/tmk/...
August 28, 2025 at 3:33 PM
Quantum Optics Lecture Notes v0.5: the main addition is Appendices K and L on the classical "semiparametric Cramer-Rao bound." (1/2)
www.ece.nus.edu.sg/stfpage/tmk/...
www.ece.nus.edu.sg/stfpage/tmk/...
www.ece.nus.edu.sg/stfpage/tmk/...
www.ece.nus.edu.sg/stfpage/tmk/...
A random memory: when I was an undergrad I went to an optics professor for advice; one question I asked was whether I could do research in theoretical optics. He looked at me with disgust and said, "there's nothing left to do in theoretical optics."
August 7, 2025 at 3:06 PM
A random memory: when I was an undergrad I went to an optics professor for advice; one question I asked was whether I could do research in theoretical optics. He looked at me with disgust and said, "there's nothing left to do in theoretical optics."
Quantum Optics Lecture Notes v0.4:
A4 size: www.ece.nus.edu.sg/stfpage/tmk/...
Letter size: www.ece.nus.edu.sg/stfpage/tmk/...
Added some appendices on open quantum systems and classical statistics. Updated the appendix on probability.
A4 size: www.ece.nus.edu.sg/stfpage/tmk/...
Letter size: www.ece.nus.edu.sg/stfpage/tmk/...
Added some appendices on open quantum systems and classical statistics. Updated the appendix on probability.
www.ece.nus.edu.sg
July 31, 2025 at 4:10 AM
Quantum Optics Lecture Notes v0.4:
A4 size: www.ece.nus.edu.sg/stfpage/tmk/...
Letter size: www.ece.nus.edu.sg/stfpage/tmk/...
Added some appendices on open quantum systems and classical statistics. Updated the appendix on probability.
A4 size: www.ece.nus.edu.sg/stfpage/tmk/...
Letter size: www.ece.nus.edu.sg/stfpage/tmk/...
Added some appendices on open quantum systems and classical statistics. Updated the appendix on probability.
www.physics.nus.edu.sg/faculty/lo-h... Singapore is the hottest place to do physics now!
www.physics.nus.edu.sg
July 25, 2025 at 5:33 AM
www.physics.nus.edu.sg/faculty/lo-h... Singapore is the hottest place to do physics now!
I heard many talks recently about bounds, and people would just write down inequalities and pretend that they are cool. One famous example is the Cramer-Rao bound for biased estimators en.wikipedia.org/wiki/Cram%C3.... (1/n)
Cramér–Rao bound - Wikipedia
en.wikipedia.org
July 25, 2025 at 4:52 AM
I heard many talks recently about bounds, and people would just write down inequalities and pretend that they are cool. One famous example is the Cramer-Rao bound for biased estimators en.wikipedia.org/wiki/Cram%C3.... (1/n)
Forgive me if I prefer quantum thermodynamics in the 70's [Lindblad (1975)]
July 12, 2025 at 4:59 PM
Forgive me if I prefer quantum thermodynamics in the 70's [Lindblad (1975)]
Stop treating the academia like a game; it ends up embarrassing everyone at the institution and not just the offenders. Reputation is hard to build and easy to destroy.
‘Give a positive review’: Hidden AI prompt found in academic paper by NUS researchers
The AI prompt is visible only when highlighted in blue. Read more at straitstimes.com. Read more at straitstimes.com.
www.straitstimes.com
July 11, 2025 at 6:59 AM
Stop treating the academia like a game; it ends up embarrassing everyone at the institution and not just the offenders. Reputation is hard to build and easy to destroy.
I heard people are interested in quantum sensing of time-varying signals again, so it's time for yet another round of shameless self-promotion: doi.org/10.1103/Phys... doi.org/10.1103/Phys... doi.org/10.1088/1367... doi.org/10.1103/Phys... doi.org/10.1103/Phys... (1/2)
Fundamental Quantum Limit to Waveform Estimation
We derive a quantum Cram\'er-Rao bound (QCRB) on the error of estimating a time-changing signal. The QCRB provides a fundamental limit to the performance of general quantum sensors, such as gravitatio...
doi.org
July 9, 2025 at 11:41 AM
I heard people are interested in quantum sensing of time-varying signals again, so it's time for yet another round of shameless self-promotion: doi.org/10.1103/Phys... doi.org/10.1103/Phys... doi.org/10.1088/1367... doi.org/10.1103/Phys... doi.org/10.1103/Phys... (1/2)
Three recent experimental demonstrations of quantum-inspired superresolution spectroscopy: arxiv.org/abs/2506.20514 arxiv.org/abs/2506.20416 arxiv.org/abs/2506.22767
Super-resolving frequency measurement with mode-selective quantum memory
High-precision optical frequency measurement is indispensable to modern science and technology, yet conventional spectroscopic techniques struggle to resolve spectral features narrower than their band...
arxiv.org
July 5, 2025 at 3:07 AM
Three recent experimental demonstrations of quantum-inspired superresolution spectroscopy: arxiv.org/abs/2506.20514 arxiv.org/abs/2506.20416 arxiv.org/abs/2506.22767
This will be handy for the new pope
May 10, 2025 at 11:14 AM
This will be handy for the new pope
Quantum Optics Lecture Notes v0.3.1
A4 size: www.ece.nus.edu.sg/stfpage/tmk/...
Letter size: www.ece.nus.edu.sg/stfpage/tmk/...
Updates after teaching PC4246 this semester. Clarifications of common issues, various improvements, and many bug fixes; see cover page for details.
A4 size: www.ece.nus.edu.sg/stfpage/tmk/...
Letter size: www.ece.nus.edu.sg/stfpage/tmk/...
Updates after teaching PC4246 this semester. Clarifications of common issues, various improvements, and many bug fixes; see cover page for details.
www.ece.nus.edu.sg
April 28, 2025 at 7:06 AM
Quantum Optics Lecture Notes v0.3.1
A4 size: www.ece.nus.edu.sg/stfpage/tmk/...
Letter size: www.ece.nus.edu.sg/stfpage/tmk/...
Updates after teaching PC4246 this semester. Clarifications of common issues, various improvements, and many bug fixes; see cover page for details.
A4 size: www.ece.nus.edu.sg/stfpage/tmk/...
Letter size: www.ece.nus.edu.sg/stfpage/tmk/...
Updates after teaching PC4246 this semester. Clarifications of common issues, various improvements, and many bug fixes; see cover page for details.
Two pandemic-era papers I neglected to promote earlier: (1) For quantum objects that arrive randomly and rarely, the Poisson state is an approximation that leads to neat formulas for many information quantities. doi.org/10.22331/q-2... (1/n)
Poisson Quantum Information
Mankei Tsang,
Quantum 5, 527 (2021).
By taking a Poisson limit for a sequence of rare quantum objects, I derive simple formulas for the Uhlmann fidelity, the quantum Chernoff quantity, the relative en...
doi.org
April 23, 2025 at 4:58 AM
Two pandemic-era papers I neglected to promote earlier: (1) For quantum objects that arrive randomly and rarely, the Poisson state is an approximation that leads to neat formulas for many information quantities. doi.org/10.22331/q-2... (1/n)
Talagrand, Quantum Field Theory, Appendix I on Gupta–Bleuler
April 9, 2025 at 1:39 PM
Talagrand, Quantum Field Theory, Appendix I on Gupta–Bleuler
New application of quantum-inspired superresolution!
March 19, 2025 at 3:16 AM
New application of quantum-inspired superresolution!
An underappreciated invention by Horace Yuen and Vincent Chan: the balanced homodyne detector [ opg.optica.org/ol/abstract.... ], which I covered today in a Quantum Optics class. Simple, elegant, works in practice.
Noise in homodyne and heterodyne detection
Quantum-mechanical calculations of the mean-square fluctuation spectra in optical homodyning and heterodyning are made for arbitrary input and local-oscillator quantum states. In addition to the unavo...
opg.optica.org
March 14, 2025 at 6:38 AM
An underappreciated invention by Horace Yuen and Vincent Chan: the balanced homodyne detector [ opg.optica.org/ol/abstract.... ], which I covered today in a Quantum Optics class. Simple, elegant, works in practice.