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Research news

  • Figure 1: A colloidal particle in an optical trap (shown as a red ball), in the presence of thermal noise, can be made to work as a microscopic machine or heat engine. Its fluctuations have some typical features, some of which are shown here. Ref: Phys. Rev. Lett. 122, 140601 Efficiency fluctuations in microscopic machines 2019-04-15 Results of a recent study by physicists from Stockholm University in collaboration with researchers at Nordita and the University of Bielefeld, provide a general understanding of the efficiency fluctuations in microscopic machines.
  • Steering is an essential feature of non-locality in quantum theory 2018-10-15 A physical theory is called non-local when observers can produce instantaneous effects over distant systems. Non-local theories rely on two fundamental effects: local uncertainty relations and steering of physical states at a distance. In quantum mechanics, the former one dominates the other in non-local games. A new study proved that the entanglement-based steering also plays an important role.
  • A schematic showing the band spectrum for a non-Hermitian Chern insulator, which is insulating in the bulk but supports chiral, electronic states on its edges. The gray spectrum corresponds to the eigenvalues of the Hamiltonian with periodic boundary conditions, while the blue corresponds to the eigenvalues of the Hamiltonian on a cylinder. The red corresponds to the chiral, edge state. Strikingly, the spectrum of the system with periodic boundary conditions is vastly different from the spectrum with open boundary conditions. Using the biorthogonal properties of the open system, however, the new theory can accurately predict when it attaches to the bulk spectrum, indicated by the orange and green dashed lines. Topology of non-Hermitian systems unraveled 2018-10-02 The study of topological materials has been an important task in condensed matter physics over the past few decades and was the subject of the 2016 Nobel prize in physics. Recent experiments and theoretical works have shown that unexpected phenomena occur in many open, non-equilibrium and complex systems that can be described using non-Hermitian physics.
  • Ana Predojevic and Markus Hennrich will be coordinating two of the projectes funded by QuantERA ERA-NET Two prestigious Quantum Technology grants for Fysikum 2018-05-16 Fysikum has been very successful in the highly competitive QuantERA ERA-NET Confund call in Quantum Technologies. Two proposals coordinated by Ana Predojevic and Markus Hennrich, at Fysikum, Stockholm University, have been selected for funding.
  • A schematic of the approach used to capture water dynamics on the ultrafast timescale. If one were able to photograph the molecules in real space with different exposure times, the image would become gradually blurry because of the motion of the molecules. This is done with x-ray scattering in the so-called reciprocal space, where the diffraction pattern is gradually smoother for longer pulse durations.  (Image credits: Fivos Perakis/Stockholm University) The Ultrafast Dance of Liquid Water 2018-05-15 It is normally considered that water molecules in the liquid state move randomly on ultrafast timescales due to thermal fluctuations. Researchers at Stockholm University have now discovered an unexpected correlated motion in water dynamics on a sub-100 femtoseconds timescale.

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Sven Mannervik
Head of the Department of Physics

Tel: 08 5537 8650
e-mail: mannervi@fysik.su.se

Research Divisions

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Chemical physics division
Condensed Matter and Quantum Optics
Cosmology, Particle Astrophysics and Strings
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