Invented a half-century ago by Nobel laureate Wolfgang Paul, the quadrupole mass filter has become an integral part of some of the most sophisticated mass spectrometers. Consisting of four parallel ...

Figure 1: Quadrupole topological insulator. The measured power absorptance spectrum (the ratio of absorbed power to incident power) of an isolated unit cell is shown in Fig. 2b; see Methods for ...

The Nature Index 2025 Research Leaders — previously known as Annual Tables — reveal the leading institutions and countries/territories in the natural and health sciences, according to their output in ...