Category: News

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]

A recording of my seminar “Resolving starlight: a quantum perspective” at the Kavli Institute for Theoretical Physics (KITP), University of California-Santa Barbara (under the program “New Directions in Quantum Metrology“) on 13 Sep, 2023 is here:

https://online.kitp.ucsb.edu/online/qmetro23/tsang/

The slides can be found at the website above or here.

Xiao-Jie Tan, Luo Qi, Lianwei Chen, Aaron J. Danner, Pakorn Kanchanawong, and Mankei Tsang, “Quantum-inspired superresolution for incoherent imaging,” Optica 10, 1189-1194 (2023). [Open Access]

Experiment on quantum-inspired superresolution by our student Xiao-Jie Tan and postdoc Luo Qi. Using spatial-mode demultiplexing (SPADE), we demonstrate that we are able to find the locations of two subdiffraction point sources accurately, not just their separation. For extended objects that consist of multiple point sources, we also demonstrate that we are able to estimate their properties in terms of the moments.

Still very classical and proof-of-concept, but Luo Qi and Xiao-Jie Tan are working hard to demonstrate something more significant in the next few months.