Gregory Korchemsky, Zoltan Bajnok and Bercel Bordis have recently developed a new general method for systematically calculating a class of observables in strongly coupled four-dimensional supersymmetric gauge theories.

Antoine Bourget, theoretical physicist at the IPhT, at work on quivers. (Credits: IPhT / R. Guida).         An international research team, including Antoine Bourget (IPhT, CEA Saclay), Marcus Sperling (University of Vienna) and Zhenghao Zhong (University of Oxford), has captured the interest of the scientific community with innovative results in quantum field theory (QFT). Their study reinterprets and generalizes the Higgs mechanism, responsible for elementary particle mass and phase transitions, using the concept of magnetic quivers. The work is published in the prestigious scientific journal Physical Review Letters [1]. A quiver is a graph made up of nodes and arrows connecting them. The arrows represent quantum fields, while the nodes symbolize the interactions (strong, weak or electromagnetic) between the fields. This reformulation makes it possible to analyze the properties of QFTs using the formalism of string and brane theory.

A workshop on quantum gravity and conformal field theory was co-organized by IPhT researchers Dalimil Mazáč and Eric Perlmutter.

A collaboration between IRFU/DPhN and IPhT proposes to detect for the first time the anisotropy of velocities before equilibrium in the plasma of quarks and gluons.

Figure: momentum per particle versus number of particles seen in a collision between two nuclei of lead atoms at the LHC. Both quantities are normalized by their values in the 5% most central collisions. The increase predicted by IPhT physicists (Gardim at al.) in ultracentral collisions (to the right) is verified by the CMS collaboration at CERN (red symbols). The speed of sound squared, cs2, is the relative slope of the right part of the curve. Credits CERN/CMS. CC-BY-4.0 Collisions between nuclei of lead atoms are carried out at the Large Hadron Collider (LHC) at CERN to study the quark-gluon plasma, a state of matter where neutrons and protons are dissociated into their elementary constituents, quarks and gluons. Its temperature at the LHC has been measured to be (2.540+-0.090) trillion Kelvin [1], [3].

A recent result [1] from researchers at IBM Quantum and IPhT shows that, for a quantum processor based on superconducting qubit technology, it is possible to model precisely and quantitatively the dynamics and loss of quantum coherence of the qubits over time, and gives fine-grained information both on the action of the environment and on unwanted interactions between the qubits.

Topological insulator (TI) states are 3D quantum phases of matter that are insulating in their bulk and conducting on their 2D surfaces. Because their unique conducting 2D surface states can be detected in STM and photoemission experiment, real solid-state materials hosting TI phases were experimentally identified almost immediately after their theoretical proposal. In the 15 years since the discovery of TIs, we have since learned that thousands of other materials host topological features, but through mechanisms that are distinct from the theory underpinning TIs. In particular, it was recently discovered that of the bulk-insulating topological materials in Nature, most are in fact topological crystalline insulators (TCIs), which unlike TIs, have both insulating 3D bulks and 2D surfaces, and at most host conducting 1D channels on their edges or "hinges."