Karen Astrid Hallberg (born May 10, 1964) is an Argentine scientist and professor of physics at the Balseiro Institute.

For her doctoral studies Hallberg worked on computational models of quantum materials that demonstrate low dimensional magnetism and superconductivity.

[5][11] After her PhD, Hallberg moved to Germany to work as a postdoctoral researcher at the Max Planck Institute for Solid State Research (MPI-FKF) and at the Max Planck Institute for the Physics of Complex Systems (MPI-PKS).

[17][18] She has studied superconductivity, magnetic order and spin-orbit coupling in complex materials and electronic transport in nanoscopic systems.

She was Director of the Condensed Matter Department at the Atomic Center in Bariloche, editor of the journal Europhysics Letters,[27] member of the Board of Directors of the Aspen Science Center, Argentine representative and Board Chair of the Latin American Center of Physics (CLAF), Vice Chair of the Low Temperature Commission of the International Union of Pure and Applied Physics (IUPAP), member of the Argentine Physical Association (AFA) Steering Committee and coordinator of the Women in Physics and Ethics subcommittees and the representative of the Argentine Branch to the International Institute for Complex Adaptive Matter (ICAM).

Her awards and honors include: Hallberg is married to physicist Ingo Allekotte, with whom she has two children.