Emil Johansson Bergholtz Professor
Contact
Name and title: Emil Johansson BergholtzProfessor
Phone: +46855378035
ORCID0000-0002-9739-2930 Länk till annan webbplats.
Workplace: Department of Physics Länk till annan webbplats.
Visiting address Room A4:1037Roslagstullsbacken 21
Postal address Fysikum106 91 Stockholm
About me
Emil J. Bergholtz (full name: Carl Erik Emil Johansson Bergholtz) is Professor of Theoretical Physics at Stockholm University. My research focuses on collective phenomena in quantum many-particle systems, particularly under extreme conditions. My work draws together ideas from mathematics, high-energy physics, materials science, photonics, cold atoms, and complex systems in the search for novel emergent behavior. While such discoveries may eventually inspire new technologies, my primary motivation is to understand the underlying principles.
After eight years abroad—as Distinguished PKS Fellow at the Max Planck Institute for the Physics of Complex Systems in Dresden and Emmy Noether Group Leader at the Free University of Berlin—I returned to Stockholm University in 2016 through the Wallenberg Academy Fellows program. I became full professor in 2019 and was appointed Wallenberg Scholar in 2024.
In 2022, I was awarded the Göran Gustafsson Prize in Physics by the Royal Swedish Academy of Sciences, “for his innovative research on topological phases and quantum materials,” recognizing my contributions to the theory of low-dimensional systems and non-Hermitian topological phenomena.
My group’s research focuses on topological phases of matter, including fractional quantum Hall states, fractional Chern insulators in moiré materials, non-Hermitian systems, and open quantum systems. We employ a mix of analytical theory and large-scale numerical simulations, and we collaborate with leading experimental groups. Former group members have gone on to professorships, group leader positions, and prestigious fellowships in Europe, China, India, and the United States. More information about current and former group members can be found on our group page and below under Research.
A growing part of our research is explicitly connected to quantum technologies. A particular focus is on quantum sensing, robust quantum platforms in moiré and other quantum materials, and dissipative or measurement-based dynamics relevant for quantum control and simulation. These directions are also at the heart of QUANTA (Quantum Technology Alliance: From Fundamental Science to Future Applications), a strategic research area that I lead together with partners at Linköping University and Uppsala University, recommended in 2026 by the Swedish Research Council for government funding starting 2027. Read more.
At Stockholm University, I also teach courses in Quantum Mechanics and Quantum Field Theory, alongside specialized research seminars. With my group, I strive to cultivate a collaborative and curious environment where bold ideas are encouraged, interdisciplinary connections thrive, and theory remains closely linked to experiment while retaining its creative and exploratory freedom.
The past few years I have taught Advanced Quantum Mechanics, and presently I also lead more specialized research seminars and a course in Quantum Field Theory for Condensed Matter Systems.
We work broadly in theoretical physics with an emphasis on collective quantum mechanical phenomena that occur in systems with a macroscopic number of particles. Most saliently, we study quantum many-particle systems for which topology, entanglement and interactions play important roles. These include fractional quantum Hall states, geometrically frustrated magnets, non-equilibrium systems, Weyl semimetals and various instances of flat band models. A common feature in these systems is that their low-energy quasiparticles bear little or no resemblance to their electronic constituents. Instead, the quasiparticles have intriguing properties such as fractional charge and statistics. To understand these notoriously complex systems we use a combination of analytical and numerical methods, beyond standard many-body theory, including exact diagonalization, field theory, strong coupling expansions etc., we occasionally adopt new methods and concepts from quantum information theory, including entanglement quantifiers and tensor networks, and contemporary mathematics, such as compressed sensing.
Our research brings together several frontiers of basic science, while at the same time having the potential to provide the basis of future technological advances.
My research group presently consists of the team displayed on our group page.
Group alumni include
PhD Students:
Ahmed Abouelkomsan, PhD 2023. Next postdoc with Liang Fu at MIT.
Elisabet Edvardsson, PhD 2023. Next permanent researcher at FOI, Stockholm.
Marcus Stålhammar, PhD 2022. Next Nordita Fellow, now Postdoc at Uppsala and Utrecht Universities.
Flore Kunst, PhD 2019 (winner of the Sigrid Arrhenius Prize from Stockholm University as well as the Oseen Medal of the Swedish Physical Society for the best Swedish physics PhD thesis). Next postdoc fellowship at MPQ Munich and Harvard; from 2021 group leader at MPI-MPL, Erlangen and now incoming chaired full professor (W3) at FAU Erlangen.
Maximilian Trescher, PhD 2018. Next: computer scientist in Berlin.
Jörg Behrmann, 2013-2017. Next: permanent staff scientist at FU Berlin.
Postdocs and researchers:
Paolo Molignini Postdoc 2022-2024. Next: VR Starting grant & group leader at SU and Assistant Professor at University of Jyväskylä, Finland.
Fan Yang Postdoc 2020-2022. Next: EPFL, Lausanne. Now researcher at SU.
Daniel Varjas Postdoc 2020-2022. Next MPI-PKS, Dresden; Now group leader and faculty member at Budapest University of Technology and Economics.
Qing-Dong Jiang Researcher 2020-2021. Next Associate Professor at the TD Lee Institute and Shanghai Jiao Tong University, Shanghai.
Ipsita Mandal, Researcher 2020-2021. Next: Associate Professor at the Polish Academy of Sciences. Now Asst. Professor at Shiv Nadar Institute of Eminence, India.
Johan Carlström, Postdoc 2017-2019. Next independent PI at SU with VR starting grant. Now researcher at KTH.
Yaron Kedem, Postdoc 2016-2019. Next: postdoc with Frank Wilczek at SU. Now in industry.
Zhao Liu, Postdoc 2015-2017. Next Thousand Talents Awardee & Assistant Professor at Zhejiang University, Now tenured Associate Professor at Zhejiang University.
Publications See Google Scholar for publications and links to frequent collaborators.
An updated list of publications is available at Google Scholar.