A4 size: https://www.ece.nus.edu.sg/stfpage/tmk/Quantum_Optics_v0.3.1.pdf

Letter size: https://www.ece.nus.edu.sg/stfpage/tmk/Quantum_Optics_v0.3.1_letterpaper.pdf

Updates after teaching PC4246 this semester. Clarifications of common issues, various improvements, and many bug fixes; see cover page for details. Major updates:

1. Many students confuse the abstract Hilbert-space operators applicable to the abstract kets and bras (“Q-numbers”) with concrete derivatives applied to c-number functions, so Sec. 3.3 adds a clarification.
2. The derivation of some Schrodinger-picture results is improved.
3. The discussion of the CHSH inequality is now based on the CHSH game.

M. Tsang, “Quantum reversal: a general theory of coherent quantum absorbers,” Quantum 9, 1650 (2025) [PDF]. Go to the journal website for a popular summary.

https://www.we-heraeus-stiftung.de/veranstaltungen/multiparameter-quantum-sensing-and-metrology/main/

I will be giving a talk at the workshop. Food and lodging are free for all participants. Application deadline is November 28.

Mankei Tsang, “Quantum Onsager relations,” Quantum Science and Technology 10, 015015 (2024); https://doi.org/10.1088/2058-9565/ad8513.

A preprint, before a minor revision was accepted, is available at https://arxiv.org/abs/2403.12896.

This work generalizes the celebrated Onsager relations in statistical physics using Fisher information in parameter estimation theory, revealing a remarkable connection between the two areas.

Bug fixes.

A4 paper size: https://www.ece.nus.edu.sg/stfpage/tmk/Quantum_Optics_v0.2.1.pdf

US letter paper size: https://www.ece.nus.edu.sg/stfpage/tmk/Quantum_Optics_letterpaper_v0.2.1.pdf

I am sharing the lecture notes for an undergraduate course PC4246 Quantum Optics that I will be teaching at NUS next semester:

https://www.ece.nus.edu.sg/stfpage/tmk/Quantum_Optics_v0.2.pdf

Still very rough; use at your own risk. Comments welcome. I include only topics that are essential in my humble and very biased opinion and I have to omit many other important topics; apologies if I omit your favorites. The course will cover Chapter 1-12. Chapter 13 is the beginning of an attempt to bridge between the basics and my own research; hope to add more chapters in the future.

Our latest work on quantum conditional expectations is published in Quantum:

This work is a continuation of the following:

I gave a talk on the basic idea at the University of Toronto on Nov 10; the recording is here:

https://www.youtube.com/watch?v=dAkvLLvhlTw

and the slides are here:

https://drive.google.com/file/d/1GpNSbcrr-MI7cTqkTY32nWYck76mdGe6/view?usp=drive_link

1. “Resolving starlight: a quantum perspective,” CQIQC/QO/AMO Seminar, University of Toronto, Canada, Oct 20, 2023: https://www.youtube.com/watch?v=458pYv8QVtE. [Slides PDF]
2. “Quantum waveform estimation, detection, and noise spectroscopy,” KITP Conference “Frontiers of Quantum Metrology,” UCSB, USA, Oct 12, 2023: https://online.kitp.ucsb.edu/online/qmetro-c23/tsang/. [Slides PDF]