Home on Xavier Waintal

A new website

Tue, 29 Sep 2026 00:00:00 +0000

After many years with an old hand-written page, here is a new website. It contains the full list of my publications (with arXiv links for everyone who does not have journal access), a collection of recorded talks, and some information for students and postdocs.

This blog will host occasional notes. Posts can contain equations, for instance the Schrödinger equation $i\hbar\,\partial_t \psi = H\psi$, or displayed ones:

$$ G^R(E) = \frac{1}{E - H - \Sigma^R(E)}. $$

Join us

Mon, 01 Jan 0001 00:00:00 +0000

I welcome applications at any time, and I answer all of them (except the generic ones sent all over the net). We typically hire one or two PhD students or postdocs every year, as well as a few master students for internships.

Who we are looking for. If you find our research interesting and have a good background in theoretical physics (condensed matter, quantum physics, statistical physics) or in applied mathematics, and you enjoy programming, please drop me a line. Much of our work is numerical, strongly interlinked with theory, and often ends up in open-source software, so a taste for both is a real plus.

Projects

Mon, 01 Jan 0001 00:00:00 +0000

Software

Kwant: a Python package for quantum transport in tight-binding systems, developed with Christoph Groth (CEA Grenoble), Michael Wimmer and Anton Akhmerov (TU Delft). A Kwant script looks very much like the equations one writes on the blackboard. Paper · video abstract.
Tkwant: the time-dependent extension of Kwant, for simulating time-resolved quantum transport, developed with Thomas Kloss and Christoph Groth. Paper.
xfac and tensor4all: libraries for tensor cross interpolation and quantics tensor trains, developed within the tensor4all collaboration, notably with Yuriel Núñez Fernández, Marc K. Ritter, Hiroshi Shinaoka and Jan von Delft. Paper.
KNIT (historical): our first open-source quantum transport code, now superseded by Kwant. Paper · download release 1.2 (tar.gz, 5.5 MB) · user guide (pdf).

Initiatives

House of Quantum Alps (Maison du Quantique Alpes), of which I am currently the director. It brings together researchers and industrial partners around quantum computing and quantum-inspired methods, with a focus on applications.
Intrica Computing: a project, based in Geneva and supported by Innosuisse, that aims at bringing quantum-inspired (tensor network) methods to industrial applications. It is led by Julian Thoenniss; I am involved as co-founder and scientific advisor.
SciPost: I am a fellow editor of this open-access journal.

Useful links

PHELIQS laboratory (CEA / Université Grenoble Alpes)
QuantAlps, the Grenoble quantum federation
Tensor network learning workshop (Grenoble, 2025)
Google Scholar profile · ORCID

Publications

Mon, 01 Jan 0001 00:00:00 +0000

All my publications, newest first. Almost all of them are freely available on arXiv; each entry has a link to the journal (when published) and to arXiv. See also my Google Scholar profile.

Research

Mon, 01 Jan 0001 00:00:00 +0000

Most of what we do lies at the border between theory and numerics. We like numerical methods that follow closely what one would do analytically: understand which mathematical structure makes a calculation possible, then teach the computer to do it. We also care about lowering the entry cost of new calculations, so that one can describe a problem the way one writes it on the blackboard. Much of this ends up in open-source software, developed with Christoph Groth, the scientific software developer of our team, with whom I work daily.

Short bio

Mon, 01 Jan 0001 00:00:00 +0000

Feel free to copy the text below (for a seminar announcement, for instance).

One sentence

Xavier Waintal is a theoretical physicist and director of research at CEA Grenoble (PHELIQS, Université Grenoble Alpes), where he works on quantum nanoelectronics, out-of-equilibrium quantum many-body physics, tensor networks and quantum computing.

One paragraph

Xavier Waintal is a theoretical physicist and director of research at CEA Grenoble, in the PHELIQS laboratory of Université Grenoble Alpes. He graduated from École Polytechnique, obtained a master’s degree in theoretical physics at École Normale Supérieure (Paris), and did his PhD with Jean-Louis Pichard at CEA Saclay (1999). After a postdoc with Piet Brouwer at Cornell University, he joined CEA Saclay in 2002 and moved to CEA Grenoble in 2009, where he headed the theory group of his laboratory (INAC/SPSMS, which became PHELIQS in 2016) from 2010 to 2018. His work lies at the border between theory and numerics and has touched quantum nanoelectronics, spintronics, out-of-equilibrium quantum many-body physics, strongly correlated systems, quantum computing and, more recently, tensor network techniques. He is one of the authors of the open-source quantum transport packages Kwant and Tkwant. He is currently the director of the House of Quantum Alps (Maison du Quantique Alpes) in Grenoble.

Talks and videos

Mon, 01 Jan 0001 00:00:00 +0000

Recorded talks, lectures and a few things for a general audience. FR marks the ones in French.