Benjamin Roussel

I am a postdoc within the Quantum Transport group led by Christian Flindt at Aalto University (Finland). My research activities concern fundamental theoretical research on various aspects of quantum mechanics. Lately, I have been interested in the electronic transport in presence of superconductors.

More generally, I am interested in quantum physics from the foundations to the intriguing emerging phenomena it leads to. This has led me to develop various research topics beyond electronic transport. Among my interests are relativistic quantum field theory and the quantum-to-classical transition. Besides my day-to-day research, I am co-writing a book on the relationships between quantum mechanics, information theory and computation theory.

More information

Publications

Articles

• B. Roussel, P. Burset & C. Flindt, arXiv preprint 2312.13829 (2023) [arXiv]
• P. Burset, et al, arXiv preprint 2312.13145 (2023) [arXiv]
• A. Feller, et al, arXiv preprint 2306.14745 (2023) [arXiv]
• R. Bardenet, et al, arXiv preprint 2210.05522 (2022) [arXiv]
• A. Feller, et al, Phys. Rev. Lett. 126, 188901 (2021) [Journal] [arXiv]
• B. Roussel, et al, PRX Quantum 2, 020314 (2021) [Journal] [arXiv]
• A. Feller, G. Cœuret Cauquil & B. Roussel, Phys. Rev. A 101, 062107 (2020) [Journal] [arXiv]
• B. Roussel & A. Feller, Phys. Rev. D 100, 045016 (2019) [Journal] [arXiv]
• R. Bisognin, et al, Nature communications 10, 1-12 (2019) [Journal] [arXiv]
• C. Cabart, et al, Phys. Rev. B 98, 155302 (2018) [Journal] [arXiv]
• B. Roussel, et al, Phys. Status Solidi (b), 1600621 (2017) [Journal] [arXiv]
• A. Marguerite, et al, Phys. Rev. B 94, 115311 (2016) [Journal] [arXiv]
• B. Roussel, P. Degiovanni & I. Safi, Phys. Rev. B 93, 045102 (2016) [Journal] [arXiv]
• É. Thibierge, et al, Phys. Rev. B 93, 081302 (2016) [Journal] [arXiv]
• D. Ferraro, et al, Phys. Rev. Lett. 113, 166403 (2014) [Journal] [arXiv]

Book

My interest in quantum mechanics lead me to an unprecedented adventure: cowriting a book. The project is to review quantum theory in the light of information and computation theories. It will result in two volumes, the first giving the reader an overview of the three fields as well as an introduction to quantum technologies. The second volume, more focused on foundations, will shed some light on the status of probabilities and locality in quantum mechanics.

Currently, the first volume is published, and we are writing the second one. This first edition is in French, but we hope to translate it in English at some point.

• P. Degiovanni, N. Portier, C. Cabart, A. Feller & B. Roussel, Physique quantique, information et calcul -- Des concepts aux applications, EDP Sciences (2020) [link]

Ph.D. thesis

I did my Ph.D. in theoretical physics within the Laboratoire de Physique at ENS de Lyon, under the supervision of Pascal Degiovanni. My thesis is in the field of electron quantum optics. I introduced new ways to access partial information about the manybody states of a quantum electrical current.

The first approach consists in describing the beam of electrons at the single-particle level. This allows to describe it in terms of elementary constituents (electrons and holes), a technique which is applicable from the experimental signal.

The omnipresence of electron-electron interactions offers another approach based on manybody quantities. I explored this rich physics, both looking at the radiation emitted by a quantum conductor, as well as the physics of decoherence and heat emissions in those systems.

If you are interested further in the topic, you can have a look at my manuscript.

Conferences

• Seminar (2023)
  University of Latvia, Riga, Latvia
  Invited talk on Electron quantum optics with superconductors
• Seminar (2022)
  Physikalisch-Technische Bundesanstalt, Braunschweig, Germany
  Invited talk on Electron quantum optics: manipulating electrons one by one
• CMD (2022)
  Manchester Central Convention Complex, Manchester, United Kingdom
  Oral presentation on Time-frequency representation of dynamical Andreev conversions

Contact

benjamin.roussel@aalto.fi
+358 50 4703813

Aalto University
P.O. Box 11000 (Otakaari 1B)
00076 Aalto
Finland