Quantum Dynamics (QD)

Research

The goal of the Quantum Dynamics group is to find novel quantum phenomena that may occur in future quantum materials and designed nanosystems. The phenomena we have been interested in include superfluidity, superconductivity, topological phases of matter, Bose-Einstein condensation, lasing, and strong coupling between light and matter in the nanoscale.

In our condensed matter theory research, we have discovered that superconductivity in a flat energy band is connected to the quantum metric and has a lower bound given by a topological invariant, the Chern number. We continue to explore the role of quantum geometry in condensed matter physics, especially in superconductivity.

In our photonics research where we combine experiment and theory, we have experimentally observed strong coupling between dye molecules and plasmonic light modes. Arrays of metal nanoparticles offer us great opportunities for designing the band structure and the modes of light. We have observed Bose-Einstein condensation in such a plasmonic lattice, as well as dark-mode and quasicrystal lasing associated with topological charges.

We fabricate plasmonic lattices using nanolithography and measure their optical properties in our lab, which includes a femtosecond laser setup for studies of quantum dynamics.

In the theory work, we use both analytical approaches and advanced numerical methods, such as dynamical mean field theory.

The Quantum Dynamics group collaborates globally to achieve its goals. Päivi Törmä leads two international research collaborations, SuperC 2033 which targets room temperature superconductivity, and SCOLED which aims at efficient organic LEDs, and is the co-Director of the Simons Collaboration on New Frontiers in Superconductivity. We also participate in a Future Makers project developing optical control of spin waves for energy efficient computing.

You can find below some of our publications, however click here for a full list of our Latest Publications. You can also find below Media coverage which includes public-accessible descriptions of our work and Alumni showing where people from our group have proceeded.

Media coverage

• High Topological charge lasing in quasicrystals
  K. Arjas, J.M. Taskinen, R. Heilmann, G. Salerno, and P. Törmä, Nature Communications 15, 9544 (2024)
  Highlighted in Aalto School of Science News
• Article about Päivi Törmä on the Research Council of Finland web-page (in Finnish)
• Kukka-Emilia Huhtinen received the Mikael Björnberg’s Memorial Fund 
  Prize, awarded by the Finnish Society of Sciences and Letters, and the Aalto School of Science dissertation award. Aalto News article about Kukka-Emilia Huhtinen's awards.
• Eeli Lamponen received the MSc thesis award 2023
• SuperC 2033 project received major funding
• Grazia Salerno got the Academy of Finland Academy Research Fellowship
• Suppression of Nonequilibrium Quasiparticle Transport in Flat-Band Superconductors
  V. A. J. Pyykkönen, S. Peotta, and P. Törmä, Phys. Rev. Lett. 130, 216003 (2023)
  Selected as Editors' Suggestion in Physical Review Letters
  Highlighted in Physics synopsis by the American Physical Society 
• Antti Moilanen received the Photonics Finland Best Doctoral Thesis in
  Photonics of the Year 2022 award
• Revisiting flat band superconductivity: Dependence on minimal quantum metric and band touchings
  K.-E. Huhtinen, J. Herzog-Arbeitman, A. Chew, B.A. Bernevig, and P. Törmä, Phys. Rev. B 106, 014518 (2022)
  Selected as Editors' Suggestion in Physical Review B
• Antti Moilanen received the Aalto School of Science dissertation award 2021
• Päivi Törmä obtained funding from the Future Makers program
• Magnetic on–off switching of a plasmonic laser
  F. Freire-Fernández, J. Cuerda, K. S. Daskalakis, S. Perumbilavil, J.-P. Martikainen, K. Arjas, P. Törmä, and S. van Dijken, Nature Photonics 16, 27 (2022)
  Highlighted in Nature Photonics News and Views and Aalto School of Science News.
• The President of Finland granted a decoration (Knight, First Class, of
  the Order of the White Rose of Finland) to Päivi Törmä.
• Determination of Dynamical Quantum Phase Transitions in Strongly Correlated Many-Body Systems Using Loschmidt Cumulants
  S. Peotta, F. Brange, A. Deger, T. Ojanen, and C. Flindt, Phys. Rev. X 11, 041018 (2021)
  Highlighted in Aalto School of Science news.
• Päivi Törmä elected as a member of the Academia Europaea
• Jami Kinnunen received the Teacher of the Year 2021 prize
• Grazia Salerno awarded the Marie Sklodowska-Curie Fellowship.
• Blog by Antti Moilanen about his research visit to IBM Zürich (in Finnish): Huoneenlämpötilan kvantti-ilmiöitä valjastamassa
• Aaro Väkeväinen received the Aalto School of Science dissertation award 2020
• Konstantinos Daskalakis got the ERC Starting Grant
• Sebastiano Peotta got the Academy of Finland fellowship
• Sub-picosecond thermalization dynamics in condensation of strongly coupled lattice plasmons
  A.I. Väkeväinen, A.J. Moilanen, M. Nečada, T.K. Hakala, K.S. Daskalakis, and P. Törmä, Nature Comm. 11, 3139 (2020)
  Highlighted in Aalto School of Science news.
• High-Frequency Sound in a Unitary Fermi Gas
  C. C. N. Kuhn, S. Hoinka, I. Herrera, P. Dyke, J. J. Kinnunen, G. M. Bruun, and C. J. Vale, Phys. Rev. Lett. 124, 150401 (2020)
  Highlighted in Physics viewpoint by the American Physical Society.
• Scaling and diabatic effects in quantum annealing with a D-wave device
  P. Weinberg, M. Tylutki, J.M. Rönkkö, J. Westerholm, J.A. Åström, P. Manninen, P. Törmä, and A.W. Sandvik, Phys. Rev. Lett. 124, 090502 (2020)
  Highlighted in Aalto School of Science news.
• Superfluid weight and Berezinskii-Kosterlitz-Thouless transition temperature of twisted bilayer graphene
  A. Julku, T. J. Peltonen, L. Liang, T. T. Heikkilä, and P. Törmä, Phys. Rev. B 101, 060505(R) (2020)
  Highlighted in Physics viewpoint by the American Physical Society, and Aalto School of Science news.
• Kukka-Emilia Huhtinen got the Aalto School of Science MSc thesis award 2018
• Jami Kinnunen received the Finnish Foundation for Technology Promotion teaching award 2019
• Tuomas Vanhala received the Aalto School of Science dissertation award 2019
• Päivi Törmä received the Magnus Ehrnrooth Foundation prize 2019
• Jani-Petri Martikainen received the Best Physics Teaching 2018 prize
• Päivi Törmä tells about the 2018 Millennium Technology Prize to Dr. Suntola and the ALD technology in the prize ceremony.
• Ultrafast Pulse Generation in an Organic Nanoparticle-Array Laser
  K.S. Daskalakis, A.I. Väkeväinen, J.-P. Martikainen, T.K. Hakala, and P. Törmä Nano Letters 18, 2658 (2018)
  Highlighted at Aalto School of Science news.
• Bose–Einstein condensation in a plasmonic lattice
  T.K. Hakala, A.J. Moilanen, A.I. Väkeväinen, R. Guo, J.-P. Martikainen, K.S. Daskalakis, H.T. Rekola, A. Julku, and P. Törmä Nature Physics 14, 739 (2018)
  Highlighted at Helsingin Sanomat, Aalto School of Science news, Novuslight, and Nanotechweb. 
• Blog entry about Päivi Törmä at the Finnish Physical Society site (in Finnish)
• Päivi Törmä tells about the Millennium Technology Prize and Designer Matter in Tekniikka ja Talous
• Konstantinos Daskalakis awarded Marie Skłodowska-Curie Fellowship for fabricating an organic polariton laser diode
• Lasing in dark and bright modes of a finite-sized plasmonic lattice
  T.K. Hakala, H.T. Rekola, A.I. Väkeväinen, J.-P. Martikainen, M. Nečada, A.J. Moilanen,and P. Törmä Nature Comm. 8, 13687 (2017)
  Highlighted at Helsingin Sanomat and Aalto School of Science news. See also video.
• Päivi Törmä appointed as the chair of the International Selection Committee of the Millennium Technology Prize
• Quantum dynamics group research highlighted in Helsingin Sanomat
• Päivi Törmä appointed Academy Professor
• Sebastiano Peotta awarded Marie Skłodowska-Curie Fellowship for studying flat-band superconductivity
• Jami Kinnunen received the Lecturer of the Year 2015 prize
• Superfluidity in topologically nontrivial flat bands
  S. Peotta and P. Törmä Nature Comm. 6, 8944 (2015)
  Highlighted at Aalto School of Science news
• Aalto University “Get to know professors: Päivi Törmä”
• Aalto yliopisto “Tutustu professoreihin: Päivi Törmä”
• Surface lattice resonances and magneto-optical response in magnetic nanoparticle arrays
  M. Kataja, T.K. Hakala, A. Julku, M.J. Huttunen, S. van Dijken, and P. Törmä Nature Comm. 6, 7072 (2015)
  Highlighted at Aalto School of Science news
• Strong coupling between surface plasmon polaritons and emitters: a review
  P. Törmä and W.L. Barnes Reports on Progress in Physics 78, 013901 (2015), with video abstract
• A book: Quantum Gas Experiments – Exploring Many-Body States
  P. Törmä and K. Sengstock (Editors), Imperial College Press 2015
  With a chapter on theory of spectroscopies in ultracold gases by P. Törmä
• Miikka Heikkinen received the Best Physics Doctoral Dissertation of 2014 award of Aalto University
• Plasmonic Surface Lattice Resonances at the Strong Coupling Regime
  A.I. Väkeväinen, R.J. Moerland, H.T. Rekola, A.-P. Eskelinen, J.-P. Martikainen, D.-H. Kim, and P. Törmä Nano Lett. 14, 1721 (2014)
  Nano Letters April 9, 2014 Cover
• Päivi Törmä received the ERC Advanced Grant 2013

Alumni