FY2023 Annual Report

Quantum Information Security Unit
Adjunct Professor Artur Ekert


The research focus over the last year has been on the development of the covariant quantum field theory of tachyons.

On the educational side, together with Timothy Hosgood, we have been working on the completion of the online introductory course in quantum information science. With Marcelo Terra Cunha, we have started collecting material for an overview of the most paradoxical aspects of quantum theory. I have also given a series of graduate level lectures at the 2023 Quantum Connection Summer School in Sweden and a number of popular lectures.

The unit has been proactive in attracting and facilitating contacts with entrepreneurs and investors in the broadly defined area of quantum technology and cybersecurity at OIST. This included, for example, the visit of Serg Bell, a Singaporean entrepreneur and investor, and the founder of Acronis, a Swiss cybersecurity technology company.

1. Staff

  • Megumi Ikeda, Administrative Assistant

2. Collaborations

Quantum principle of relativity

  • Prof. Andrzej Dragan  (University of Warsaw)

Quantum information science 

  • Prof. Marcelo Terra Cunha  (University of Campinas)
  • Dr Timothy Hosgood (University of Oxford)

3. Activities and Findings

Together with Andrzej Dragan and his colleagues from the University of Warsaw, we have made some progress in addressing three major misconceptions concerning quantized tachyon fields, namely the energy spectrum being unbounded from below, the frame-dependent and unstable vacuum state, and the non-covariant commutation rules. These issues were shown to be a result of misrepresenting the Lorentz group in a too small Hilbert space. By doubling this space, we managed to establish an explicitly covariant framework that allows for the proper quantization of the tachyon fields, eliminating all of these issues. This is still work in progress.

4. Publications

1. Reply to the Comment on “Quantum principle of relativity”
Andrzej Dragan, Artur Ekert
New J. Phys. 25 (2023) 12, 128002 
DOI: [10.1088/1367-2630/ad100e]

2. Covariant quantum field theory of tachyons
Jerzy Paczos, Kacper Dębski, Szymon Cedrowski, Szymon Charzyński, Krzysztof Turzyński, Artur Ekert, Andrzej Dragan
DOI: [10.48550/arXiv.2308.00450]

5. Selected Lectures and Presentations

1. The ultimate limits of privacy
USTC, Shanghai, China (19 May 2023)

2. Girolamo Cardano and his "useless" discoveries
USTC, Hefei, China (24 May 2023)

3. Bell inequalities: From Curiosity to Security
Ingarden Memorial Lecture, Torun, Poland (29 Nov 2023)

4. Quo Vadis Quantum Cryptography?
Workshop on “Quantum Science and Technology: recent advances and new perspectives” The Pontifical Academy of Science, Vatican City (30 Nov 2023)

5. Bell inequalities: From Curiosity to Security
Scientific colloquium and public lecture, Donostia International Physics Center, San Sebastian and Bilbao, Spain (7-8 Mar 2024)

6. Intellectual Property Rights and Other Specific Achievements

Nothing to report

7. Meetings and Events

Nothing to report