Research Fields

Dirac Materials

Dirac materials are characterized by the existence of low-energy excitations that can be described by the Dirac equation, usually reserved for relativistic particles. Our research focus is on the study of transport properties, pumped Dirac materials, and bosonic Dirac matter.

Dynamic orders and superconductivity

We study dynamic quantum matter as a method to unveil hidden and entangled order parameters. Examples include dynamic multi-ferroicity, odd-frequency superconductivity, and non-hermitian systems.

Materials informatics and the OMDB

We combine ab-initio calculations of organic materials with machine learning algorithms to develop predictive models for properties of organic compounds. Our open-access Organic Materials Database includes more than 40000 materials.

Dark matter detection

We develop novel platforms for the detection of axion dark matter in condensed matter systems. In particular, we propose a detector design based on multi-ferroic materials.

Highlights

odd-frequency

ODD FREQUENCY

Odd-Frequency (Berezinskii) Pairing

Odd frequency superconductivity (OFSC) or Berezinskii pairing is a nontrivial manifestation of dynamical order, where the Cooper pair amplitude is odd in relative time. This possibility extends the conventionally allowed symmetries of the pair amplitudes. It is a rich and testing playground for the dynamics of quantum matter.

persistent-homology

Materials informatics

Persistent Homology for Magnetism

We developed a systematic approach to study magnetic phase diagrams that uses persistent homology, a recent computational method that is a type of topological data analysis. This method can capture both phases with and without long range magnetic order, such as the ferromagnetic and spin ice phase. Persistent homology also provides valuable insights into different phases.

Dark Matter

Dark Matter Detection

Detecting dark matter with Dirac media

Dirac materials have a wide range of applications and have even been proposed as a sensor material for dark matter particles. The energy range accessible by the small gap in massive Dirac cones provides the sensitivity to search in the sub-MeV mass scale. The small gap filters out the background thermal noise while still capturing excitations due to dark matter

Pumped

PUMPED DIRAC MATTER

Transient excitonic condensate in pumped Dirac materials

Driven or non-equilibrium Dirac materials offer a new platform for investigation of collective instabilities. Recent pump-probe photoemission experiments on graphene and three-dimensional (3D) topological insulators (TIs) show the existence of a long-lived population inversion, a situation when photoexcited electrons and holes form two independent Fermi-Dirac distributions. Motivated by these results, we propose to search for transient excitonic instability in optically-excited DMs with population inversion.

Optics

OPTICS - DIRAC MEDIA

Light-Matter interactions in Dirac materials

The result of applying an external electromagnetic field on a medium manifests itself the creation of screening fields from within which consequently change the polarisation of the medium. The temporal dynamics of such polarisation fields then create electric currents. The relationship between the current and the external field is highly nontrivial in general, as it depends not only on the internal properties of the medium, but also on the excitation regime of the field. Low intensity fields tend to produce polarisations which scale linearly with the intensity and to generate currents oscillating at the same frequency as the external perturbation.

Dirac and Weyl

DIRAC AND WEYL SEMIMETALS

Electronic properties of Dirac and Weyl semimetals

Dirac and Weyl semimetals are unique condensed matter materials, whose low-energy electron quasiparticles are described by the relativistic-like Dirac and Weyl equations, respectively. The hallmark properties of their quasiparticle states are their linear dispersion relations and well-defined chiralities. The band structure of Dirac and Weyl semimetals contains a discrete number of touching points known as the Dirac points and the Weyl nodes, respectively.

Research Fields

Dirac Materials

Dynamic orders and superconductivity

Materials informatics and the OMDB

Dark matter detection

Highlights

Nordita

Stockholm University

KTH

UConn