Paper by Immanuel Bloch published in journal Nature
Any matter occurs in different phases, which can merge into one another. An example of this is water, which exists in liquid form, as ice or steam — depending on the external conditions. The different physical phases have the same chemical composition, but a different degree of internal order. If the temperature or pressure changes, for example, the water changes into a different phase at a certain point. However: In some materials, there are phases between which a transition is not possible because they are protected by a certain form of symmetry. Physicists refer to these as topological phases.
One example of this is the Haldane phase, named after the 2016 Nobel Prize winner in physics Duncan Haldane, which occurs in antiferromagnetic spin‑1 chains. The team of Immanuel Bloch and Timon Hilker at MPQ has now succeeded in realizing this exotic state of matter in a simple system of ultracold atoms. Using a quantum gas microscope, they brought the atomic spins into the desired shape, measured the properties of the system and thus found the hidden internal order typical of the Haldane phase.
With their results, the Max Planck researchers have not only laid the foundation for experimentally verifying theoretical predictions about topological phases. Their new findings could also find practical application in the future – in quantum computers. With the help of topological phases, it would be possible to ensure the stability of qubits, the fundamental computing units of quantum computers.
Congratulations Immanuel Bloch!